// ---------------------------------------------------------------------------
// shell/Shell.tsx — the STANDALONE React shell (wave-4 scaffold; EXIT wave 1
// gives it a real door and a real nav).
//
// WHAT THIS IS. The successor-shaped outer frame the 2026-07-23 decision named
// ("React over a thin API — the same contract the OM-6 MCP server exposes").
// It STRANGLES, it does not replace: exactly one surface is native today — the
// Customer table, the component tree the Streamlit embed already ships — and
// every other surface is an honest link into the current application. A page
// moves here when its data contract is served by the API, never before; the
// nav never pretends otherwise.
//
// WHAT CHANGED IN EXIT WAVE 1 (X5 + X6):
//   · The door is per-user (`core/users` accounts over X2/X3), not a shared
//     HTTP Basic password. SHELL.md's ladder step-1 "SANDBOX user key until
//     real auth lands" is SUPERSEDED — there are real sessions from day one.
//   · The nav is SERVER-FILTERED and registry-driven (`GET /api/v1/nav`), not a
//     static array hand-mirroring core/registry.py. What a user sees is what
//     `may_open` granted them.
//   · There is NO client-side nav fallback and no hard-coded surface. An
//     undeclared surface is denied — including by omission from the payload.
//
// WHAT THIS IS NOT. Not Next.js — recorded decision: one component tree, one
// build system (the same Vite workspace whose OTHER config builds the embed
// bundle), no SSR/SEO need behind a login gate. The shell frame is the cheap,
// swappable part; the components are the asset. Revisit at the white-label
// trigger (OM-7), where multi-tenant routing might earn Next.
//
// Routing is a ~20-line hash router on purpose: a handful of routes do not earn
// a dependency the embed bundle would have to keep excluded.
// ---------------------------------------------------------------------------

import { lazy, Suspense, useCallback, useEffect, useRef, useState } from "react";
import { createPortal } from "react-dom";
import type { MouseEvent as ReactMouseEvent, ReactNode } from "react";
/**
 * ⭐ WAVE-27 item 34 (I5) — ROUTE-LEVEL CODE SPLITTING.
 *
 * Six surfaces that are already mounted CONDITIONALLY (an automation route, the settings modal,
 * the connectors page, home, the template picker, the alerts pane) become their own chunks. The
 * shell downloads them when a person actually opens one — which for most sessions is never, and
 * for every session is not the first paint.
 *
 * ⚠ EVERY ONE OF THESE WAS ALREADY BEHIND A CONDITION IN THE JSX, and that is what makes the
 * split real rather than cosmetic: a `lazy` whose mount renders unconditionally downloads on the
 * first paint anyway and buys a Suspense boundary for nothing. `CustomerGrid` is deliberately NOT
 * in this list, for the mirror-image reason — it IS the first paint on nearly every route, so
 * splitting it would add a round trip to the common case. (The build reports it as an INEFFECTIVE
 * dynamic import from `RecordDetail`; that is expected and correct — that import exists to break
 * a module CYCLE, not to move bytes. See the note beside it.)
 *
 * ⚠ `SettingsModal` is a NAMED export, so its loader maps to `{ default }`. A default-import
 * `lazy()` over a named export fails at RUNTIME, on click, and only for that one surface.
 */
const AutomationSurface = lazy(() => import("../automation/AutomationSurface"));
import CustomerGrid from "../customer-grid/CustomerGrid";
import { clearCustomersCache, currentSurfaceScope } from "../customer-grid/apiBridge";
import { OverlayProvider } from "../customer-grid/OverlaySurface";
// ROWS_STALE_EVENT left with `addRecord` (wave 20 item 4): the shell no longer writes rows,
// so it no longer has to tell the grid that it did.
import { API_V1, AUTOMATION_OPEN_EVENT, CREDENTIALS, DATA_ERROR_EVENT, NAV_MINIMIZE_EVENT, TOAST_EVENT, UNAUTHORIZED_EVENT, VIEW_OPEN_EVENT, signal } from "../apiContract";
import { PageSurface } from "../pages/PageSurface";
const SettingsModal = lazy(() =>
  import("../settings/SettingsModal").then((m) => ({ default: m.SettingsModal })));
import type { SettingsSection } from "../settings/SettingsModal";
import { Brand } from "./Brand";
import { ErrorBoundary } from "./ErrorBoundary";
import LoginPage from "./LoginPage";
import { ASSISTANT_ROUTE, CONNECTORS_ROUTE, EMPTY_NAV_PREFS, ENVELOPE_KEYS, HOME_ROUTE, INBOX_ROUTE, MAX_NAV_FOLDERS, NAV_TIMEOUT_STATUS, appLink, canonicalRoute, databaseEntries, defaultRoute, deleteTable, fetchNav, fetchNavPrefs, fetchTableFootprint, foldNav, postOpened, QUERY_ROUTE, resolveRoute, saveNavMeta, saveNavPrefs, shapeNav, splitChrome } from "./nav";
import type { NavEntry, NavMetaPatch, NavPage, NavPrefs, Recent } from "./nav";
// ⭐ 2026-08-14 — the database frame, extracted so the Query module can wear the SAME one.
import { DbHead, DbIcon, gridScopeFor } from "./dbFrame";
const HomePage = lazy(() => import("../home/HomePage"));
const TemplatePicker = lazy(() => import("../home/TemplatePicker"));
const ConnectorsPage = lazy(() => import("../connectors/ConnectorsPage"));
// WAVE 23 C9 (W23-W2) — SESSION D's public page. A STATIC import, not a lazy one: the wave's own
// rule is that a required import fails the build when the file is not there, which is the whole
// difference between a mount and an intention (verify_wiring's header).
import FormPublic from "../forms/FormPublic";
// ⚠ EAGER, not `lazy()`, and deliberately — same call as `FormPublic` beside it. A published link
// is a stranger's FIRST request; a lazy chunk would cost them a second round trip before anything
// paints, to save a signed-in user bytes they have already paid for. The page imports nothing
// from `customer-grid/**`, so it drags no spreadsheet engine along with it.
import PublishedView from "../publish/PublishedView";
import { mergeRecents } from "../home/homeModel";
import type { AutomationTile } from "../home/homeModel";
// ⭐ WAVE 24 item 13 (R10, wiring W24-W3) — Home's Automations section.
// ⚠ WAVE 26 ITEM 18 (R14): `stateOf` came out of this import with Home's status dot. The old note
// here said it was imported rather than re-derived because it is the ONE place "is this running"
// is decided — still true, and still why nobody should re-add a local copy; the frame simply has
// no reason to ask any more. `listAutomations` brings the credentials and the error shape with
// it, so the frame adds a fetch, not a protocol.
import { listAutomations } from "../automation/automationApi";
import { CreateNewRow, FolderHead, RowMenu, SchemaDrawer } from "./NavExtras";
/** ⭐⭐ W32-T04 (R7, wiring 1): the Inbox MODULE replaces the Alerts pop-up pane. `AlertsPane` is
 *  no longer imported here — C's `W32-T21` deletes the file, and an unmounted-but-imported
 *  component is [[artifact-with-no-importer]] wearing the other mask. */
const InboxPage = lazy(() => import("../inbox/InboxPage"));
/** ⭐⭐ W32-T05 (R1, C5, wiring 2): the Query module — E's page, A's mount. */
const QueryPage = lazy(() => import("../query/QueryPage"));
/**
 * ⭐⭐ 2026-08-14 (owner item 2) — THE AI ASSISTANT, UNBOARDED.
 *
 * ⛔ AND THE `ai-agent` MODULE IS GONE, WHICH IS THE SAME DECISION SEEN FROM THE OTHER SIDE.
 * Owner, verbatim: *"Remove the 'AI agent' module completely. previous wave did not follow
 * instruction. AI assistant module IS AI agent module. So no need to separate it like that."*
 * Wave 33's own note beside that rail row had already reached the same conclusion and declined to
 * act on it (*"that row's destination IS dead … retiring it in favour of this one looks right"*),
 * raising it as ASK C-9. This is the answer to that ask: ONE AI door, and it is this one.
 *
 * ⚠ The `ai_agent` automation ACTION KIND is a different thing and stays — it is a STEP inside a
 * flow (`automation_engine.py`), not a module, and `POST /automations/draft` behind it is still
 * mounted and still gated (`api/verify_automation.py::section_w33_ai_agent`).
 */
const AssistantPage = lazy(() => import("../assistant/AssistantPage"));

/**
 * Item 34's Suspense boundary, one definition for all six surfaces.
 *
 * ⛔ THE FALLBACK IS DELIBERATELY EMPTY, and that is a design decision rather than a stub. The
 * standing R6 rule is that this product shows a shared spinner mark and never load TEXT
 * (`verify_icons` asserts it across every source file, so a "Loading..." here would go red).
 * These chunks are tens of kilobytes off the same origin that just served the shell, so the
 * honest choice between a flash of a spinner and a frame of nothing is nothing — a spinner that
 * appears and vanishes within one frame reads as a glitch, not as progress.
 *
 * ⭐ WAVE 30 (R5) — AND AN ERROR BOUNDARY, INSIDE THE HELPER RATHER THAN AT SIX CALL SITES.
 * Three of these six (`TemplatePicker`, `SettingsModal`, `AlertsPane`) are siblings of `<main>`,
 * so the content-area boundary below cannot cover them; putting it here covers all six with one
 * edit. It also catches what `Suspense` alone cannot: a REJECTED chunk fetch. `lazy()` throws its
 * rejection at render, which before today unmounted the whole product because one deploy-time
 * cache miss made a modal's JavaScript unreachable.
 */
function Lazily({ children, surface }: { children: ReactNode; surface: string }) {
  return (
    <ErrorBoundary surface={surface}>
      <Suspense fallback={null}>{children}</Suspense>
    </ErrorBoundary>
  );
}

import { createAlert, fetchInbox } from "../alerts/alertsApi";
import {
  ALERT_CREATE_EVENT,
  EMPTY_INBOX,
  badgeText,
  parseAlertCreate,
  // ⚠ `routeForTopic` left this import with the pane (W32-T04). It is still exported and still
  // used — `inboxModel.routeForTarget` is its caller now — but the FRAME no longer asks the
  // topic→route question directly, which is the point of C3: one owner for that table.
} from "../alerts/alertsModel";
import type { Inbox } from "../alerts/alertsModel";
// ⭐ W32-T04 (C3): the target→surface question lives in C's module, so the frame's
// dispatcher is a switch over two literals rather than a second copy of the route table.
import { retryEmit, routeForTarget } from "../inbox/inboxModel";
import ShareDialog from "./ShareDialog";
import { SHARE_OPEN_EVENT, parseShareRequest } from "./shareModel";
import type { ShareRequest } from "./shareModel";
// WAVE 19 R8 — the chosen database mark. Read-only across the session fence.
import { FolderMark, LockMark } from "../customer-grid/icons";
import type { FolderIcon } from "../customer-grid/types";
import { isAdmin, logout, me } from "./session";
import type { SessionUser } from "./session";

/** The current application — where every not-yet-ported surface actually runs.
 *  Deep links (`?page=<registry key>`) are the app's own, so a strangler link
 *  lands on the exact page, not a landing screen. */
const APP_BASE =
  (import.meta.env.VITE_AIOS_APP_URL as string | undefined) ??
  "https://royal-imports-cfo-os.hf.space";

/** X5's hash route. Also the route an unauthenticated shell is pinned to. */
const LOGIN_ROUTE = "login";
/** Wave 14 C-NAVFOLD — the nav drag's PRIVATE dataTransfer MIME. Private so a drop on any
 *  text-editable surface types nothing (a textarea is a native drop target for text/plain —
 *  the wave-13 C-LAYOUT scar). */
const NAV_DRAG_TYPE = "application/x-loopable-nav";

/** A stable identity for "no nav yet" — see its use below. */
const NO_ENTRIES: NavEntry[] = [];

/**
 * WAVE 23 C10 — the Database flyout's anchor, CLAMPED to the viewport.
 *
 * ⛔ `NavExtras.MenuShell` clamps both axes and this panel first did not, which is the same
 * omission with a bigger blast radius: the Database button sits ~200px down the rail and the
 * panel is up to 560px tall, so on a short laptop viewport its create footer — the three rows
 * that are the whole point of the redesign — lands below the fold with no way to scroll to it
 * (the panel's own scroll is INSIDE the list, deliberately, so the footer stays put).
 *
 * The height here is the CSS `max-height: min(70vh, 560px)`, restated. Two copies of one number
 * is a real cost; the alternative is measuring the panel after it mounts, which means rendering
 * it in the wrong place for a frame. Named and kept beside the rule it mirrors.
 */
const DBFLY_MAX_H = 560;

export function flyoutAt(rect: { right: number; top: number }, vw: number, vh: number) {
  const h = Math.min(Math.round(vh * 0.7), DBFLY_MAX_H);
  return {
    x: Math.min(Math.round(rect.right + 6), Math.max(8, vw - 268 - 8)),
    y: Math.max(8, Math.min(Math.round(rect.top), vh - h - 8)),
  };
}

/**
 * ⭐ THE ONE PLACE the Database flyout's position is measured off its button (wave-23 close-out).
 *
 * Two open-paths grew this wave — the button's own click, and "+ Create new…" opening the panel so
 * a just-named folder is visible — and each measured the element itself. That is the shape D-20
 * exists to prevent, one pattern over: **the null case and the measurement should live in exactly
 * one place**, or the second caller is one refactor away from forgetting the guard.
 *
 * ⚠ Honest note on the gate, because the fix should not be mistaken for a rename. `verify_overlay`
 * greps for a LITERAL token — a variable named `anchor`, followed by a measure call — so the
 * click-path (which reads `e.currentTarget`) always passed while the ref-path failed. The needle
 * is a proxy for "a call site measured its own anchor", and a proxy can be satisfied by renaming a
 * variable. This change satisfies it STRUCTURALLY instead: there is now one measurement, one null
 * guard, and no second call site to keep honest. Booked as DEBT (D-49) so the gate's real subject
 * (anchor-rect logic outside the overlay layer) can be tightened deliberately rather than by grep.
 *
 * ⛔ AND DO NOT SPELL THE TOKEN OUT IN THIS COMMENT. The first draft of this note quoted the exact
 * string it was describing, and the gate — which greps raw file text — matched the explanation and
 * went red on a file with no defect in it. Prose about a pattern IS the pattern to a text scan;
 * the same trap as a marker comment placed mid-selector (verify_catalog, wave 21).
 */
export function flyoutFrom(el: HTMLElement | null) {
  if (!el) return null;
  return flyoutAt(el.getBoundingClientRect(), window.innerWidth, window.innerHeight);
}

/**
 * WAVE 23 C9 (wiring W23-W2) — the PUBLIC form route: `#/form/<token>`.
 *
 * ⛔ THE TOKEN IS WHITELISTED, NOT SLICED. `secrets.token_urlsafe` mints `[A-Za-z0-9_-]`, so
 * anything else in that position is not a token this product issued — and passing it through
 * would let a crafted hash decide what `FormPublic` puts in a URL. Refusing here means the frame
 * falls through to its normal routing (and the visitor meets the login page), which is the
 * correct answer for a link that is not one of ours.
 *
 * `null` for every other route, so the branch that reads it is a single truthiness test.
 */
export function formTokenOf(route: string): string | null {
  const m = /^form\/([A-Za-z0-9_-]{8,128})$/.exec(route);
  return m ? m[1] : null;
}

/**
 * ⭐⭐ WAVE 33 item 8b (ruling R5, W33-T26) — the PUBLISHED VIEW route: `#/v/<token>`.
 *
 * The same construction as `formTokenOf` immediately above, and the same reason: the token is
 * WHITELISTED against `secrets.token_urlsafe`'s alphabet, never sliced out of the hash. Anything
 * else in that position is not a token this product minted, and passing it through would let a
 * crafted hash decide what `PublishedView` puts in a URL. Refusing here drops the frame back into
 * normal routing, where the visitor meets the login page — the right answer for a link that is
 * not one of ours.
 *
 * ⚠ `v` RATHER THAN `view`, and it is not brevity for its own sake: `#/view/...` would sit one
 * typo away from the app's own routes, while `v` is a namespace nothing else claims. R5 names
 * this exact shape.
 */
export function publishTokenOf(route: string): string | null {
  const m = /^v\/([A-Za-z0-9_-]{8,128})$/.exec(route);
  return m ? m[1] : null;
}

type Session =
  | { phase: "checking" }
  | { phase: "anon" }
  | { phase: "authed"; user: SessionUser };

type Nav =
  | { phase: "idle" }
  | { phase: "loading" }
  | {
      phase: "ready";
      entries: NavEntry[];
      utility: NavPage[];
      /** WAVE 23 C10 — the Home landing's recently-opened list, per user, off the nav payload. */
      recents: Recent[];
      empty?: string;
      /** ⭐ W31-T11 — registry keys this workspace's catalogue leaves out. Deliberate. */
      omitted?: string[];
      /** ⛔ W31-T11 — parts of the payload the SERVER could not read. Not deliberate. */
      degraded?: string[];
    }
  | { phase: "error"; timedOut?: boolean };

const NO_UTILITY: NavPage[] = [];
/** Stable identity, like `NO_ENTRIES` — a fresh `[]` per render would re-run Home's memo. */
const NO_RECENTS: Recent[] = [];

/**
 * ⭐⭐ W33-T22 (owner item 1) — THE TWO ROWS THE PAYLOAD DECIDES, FOUND IN ONE PLACE.
 *
 * ⚠ Both predicates had exactly one call site, in the render body, and now have two — the render
 * and the memory effect below. Written out here so the two cannot answer differently: "is
 * Automation on this rail?" must not be `kind === "native"` in one place and `truthy` in the
 * other, or the remembered rail reserves a slot the render never fills [[one-question-two-normalizers]].
 */
const findAnalyst = (utility: NavPage[]) => utility.find((p) => p.key === "analyst");
const findAutomation = (entries: NavEntry[]) =>
  entries.find((e) => e.key === "automation" && e.kind === "native");

/**
 * ⭐⭐ W33-T22 — WHAT THIS ACCOUNT'S RAIL LOOKED LIKE LAST TIME, so first paint need not guess.
 *
 * ⛔ THE PROBLEM A PLACEHOLDER ALONE DOES NOT SOLVE, and it was found by a reviewer reading the
 * fix rather than by any gate. Holding a slot for a conditional row fixes the common case — the
 * row lands and fills the box it was already occupying — but for an account that does NOT have
 * the surface, the slot is reserved at first paint and then COLLAPSES when `/nav` says "silent".
 * That is a flash-then-shove, i.e. arguably worse for that user than the bug we set out to fix,
 * and `silent` must keep collapsing: reserving permanent space for a surface the server did not
 * grant would be the hard-coded row this frame refuses to have (see the file header).
 *
 * ⭐ SO THE FIRST PAINT REPRODUCES THE LAST ONE. On every `ready` payload we record which of the
 * two conditional rows this account actually had; on the next load we reserve a slot only for the
 * rows it had. A returning user therefore gets their FINAL rail geometry in the first paint,
 * whichever way it goes, and `/nav` only ever confirms it.
 *
 * ⚠ KEYED BY USERNAME, NOT BY BROWSER. `aios-nav-collapsed` above is a per-BROWSER preference and
 * that is right for it; this is a per-ACCOUNT fact about permissions, and on a shared machine an
 * un-keyed version would paint one person's grants for another. `who` is known at first paint
 * because the shell is released on `/me`, which is the same fact that makes this bug possible.
 *
 * ⛔ UNKNOWN IS NOT FALSE. A first-ever load has no memory, and the honest answer there is to
 * RESERVE the slot (`pending`), not to assume absence — an absent row that then arrives is the
 * original defect. Only a remembered, explicit `false` suppresses the placeholder. Same on a
 * blocked/parse-failed storage: fall back to reserving.
 */
const RAIL_MEMORY_KEY = "aios-rail-slots";

function railMemory(who: string | null): Record<string, boolean> {
  if (!who) return {};
  try {
    const all = JSON.parse(localStorage.getItem(RAIL_MEMORY_KEY) || "{}");
    const mine = all && typeof all === "object" ? all[who] : null;
    return mine && typeof mine === "object" ? (mine as Record<string, boolean>) : {};
  } catch {
    return {};
  }
}

function rememberRail(who: string | null, slots: Record<string, boolean>) {
  if (!who) return;
  try {
    const raw = localStorage.getItem(RAIL_MEMORY_KEY);
    const parsed = raw ? JSON.parse(raw) : {};
    const all = parsed && typeof parsed === "object" ? parsed : {};
    all[who] = slots;
    localStorage.setItem(RAIL_MEMORY_KEY, JSON.stringify(all));
  } catch {
    // Storage can be blocked. The rail then falls back to reserving the slot, which is the
    // safe direction: a placeholder that turns into a row beats a row that appears from nowhere.
  }
}

function useHashRoute(): string {
  // ⭐ W32-T04 (C3): a RETIRED key is translated here, before anything reads it — so the whole
  // shell (`resolveRoute`, `active`, every `route === X` below) sees one vocabulary and no reader
  // has to know a rename happened. `canonicalRoute` is identity for every live key.
  const read = () => canonicalRoute(window.location.hash.replace(/^#\/?/, ""));
  const [route, setRoute] = useState<string>(read);
  useEffect(() => {
    const onChange = () => setRoute(read());
    window.addEventListener("hashchange", onChange);
    return () => window.removeEventListener("hashchange", onChange);
  }, []);
  return route;
}

/** A surface that still lives in the current application. Honest copy, one
 *  action — never a mock of the page it is not. */
function StranglerPage({ entry }: { entry: NavEntry }) {
  return (
    <div className="shell-placeholder">
      <h1>{entry.label}</h1>
      <p>This surface runs in the current application.</p>
      <a className="shell-link" href={entry.href} target="_blank" rel="noreferrer">
        Open {entry.label}
      </a>
    </div>
  );
}

// --- the three nav glyphs (SVG, never emoji — the platform's own rule) ------

/** The database cylinder every source-backed row carries, mirroring the host
 *  nav's Material `database` glyph. */
/**
 * ⭐ THE MAGNIFIER — the Query rail row's mark (owner, 2026-08-14: *"Change the icon for
 * Query, it should just be a magnifying glass icon"*).
 *
 * ⚠ IT REPLACES `SparkIcon` ON THAT ROW, and the row it leaves behind is the one that
 * still means "AI": the assistant. Two rows wearing the same sparkle said the two were
 * the same surface — which is exactly the confusion the owner is unwinding in this pass.
 * Stroke-only at the same 16-box as `DbIcon` / `BellIcon`, so the rail's optical weight
 * is unchanged.
 */
function SearchIcon() {
  return (
    <svg className="shell-nav-icon" viewBox="0 0 16 16" aria-hidden="true">
      <circle cx="7" cy="7" r="4.3" />
      <path d="M10.2 10.2 13.6 13.6" />
    </svg>
  );
}

/** The host's `auto_awesome` sparkle for the AI-assistant slot (app.py:8166). */
function SparkIcon() {
  return (
    <svg className="shell-nav-icon is-spark" viewBox="0 0 16 16" aria-hidden="true">
      <path d="M6.2 2.2 7.5 5.5l3.3 1.3-3.3 1.3-1.3 3.3-1.3-3.3-3.3-1.3 3.3-1.3z" />
      <path d="M12.2 9.4l.8 2 2 .8-2 .8-.8 2-.8-2-2-.8 2-.8z" />
    </svg>
  );
}

/** The new-tab affordance on a hand-off row: this destination opens in the
 *  current application, and the arrow says so before the click does. */
function ExtIcon() {
  return (
    <svg className="shell-nav-open" viewBox="0 0 12 12" aria-hidden="true">
      <path d="M4.6 3h4.4v4.4M8.8 3.2 3.2 8.8" />
    </svg>
  );
}

/* ⭐ `DbHead` AND `DbIcon` MOVED TO `shell/dbFrame.tsx` (2026-08-14), unchanged in behaviour.
   They were private to this file, and the owner's Query instruction — *"the query module should
   exactly BE looking like the database module, COMPLETELY"* — makes them a SECOND surface's
   header too. `gridScopeFor` went with them, and that one is not a move but a fix: the registry
   key and the grid scope are different spellings, and the map used to live inline in the native
   branch below where nothing else could reach it. See that file's header. */

/** The ⋯ affordance on the account row. */
function DotsIcon() {
  return (
    <svg className="shell-account-dots" viewBox="0 0 16 16" aria-hidden="true">
      <circle cx="3.5" cy="8" r="1.25" />
      <circle cx="8" cy="8" r="1.25" />
      <circle cx="12.5" cy="8" r="1.25" />
    </svg>
  );
}

/** WAVE 19 R12 — the gear beside the account menu's one Settings row. Drawn in
 *  the same 16x16 stroke vocabulary as the rest of this file (SVG, never an
 *  emoji — the platform's own rule), so it sits beside `DbIcon` and `SparkIcon`
 *  as one family rather than as an icon borrowed from somewhere else. */
function GearIcon() {
  return (
    <svg className="shell-menu-icon" viewBox="0 0 16 16" aria-hidden="true">
      <circle cx="8" cy="8" r="2.15" />
      <path d="M8 1.9l.9 1.5 1.7-.4.5 1.7 1.7.5-.4 1.7 1.2 1.1-1.2 1.1.4 1.7-1.7.5-.5 1.7-1.7-.4-.9 1.5-.9-1.5-1.7.4-.5-1.7-1.7-.5.4-1.7L1.7 8l1.2-1.1-.4-1.7 1.7-.5.5-1.7 1.7.4z" />
    </svg>
  );
}

/** WAVE 19 R10 — Automation's own mark, now that it is a standalone rail button
 *  rather than a row in the database list. Two nodes and the edge between them:
 *  a flow, which is what the surface actually is, and visibly not a database. */
function AutoIcon() {
  return (
    <svg className="shell-nav-icon" viewBox="0 0 16 16" aria-hidden="true">
      <rect x="1.9" y="5.4" width="4.6" height="5.2" rx="1.1" />
      <rect x="9.5" y="5.4" width="4.6" height="5.2" rx="1.1" />
      <path d="M6.5 8h3" />
    </svg>
  );
}

/** WAVE 20 item 25 — the Alerts row's mark. A bell, in the same 16x16 stroke
 *  vocabulary as its neighbours, so it sits beside the sparkle and the flow rather
 *  than arriving from another icon set. */
function BellIcon() {
  return (
    <svg className="shell-nav-icon" viewBox="0 0 16 16" aria-hidden="true">
      <path d="M8 2.4a3.5 3.5 0 0 1 3.5 3.5v2.3l1.2 2H3.3l1.2-2V5.9A3.5 3.5 0 0 1 8 2.4Z" />
      <path d="M6.6 12.4a1.5 1.5 0 0 0 2.8 0" />
    </svg>
  );
}

/** WAVE 23 R7 — Home's mark. A house, in the same 16x16 stroke vocabulary as its neighbours;
 *  the reference rail uses one and there is no more literal glyph for "the landing". */
function HomeIcon() {
  return (
    <svg className="shell-nav-icon" viewBox="0 0 16 16" aria-hidden="true">
      <path d="M2.4 7.2 8 2.6l5.6 4.6" />
      <path d="M3.9 8.2v5.2h8.2V8.2" />
    </svg>
  );
}

/** WAVE 23 R8 — Connectors: two links of a chain, which is exactly what a connector is. The
 *  same glyph the Home card draws, so the nav row and the card that leads to it agree. */
function PlugIcon() {
  return (
    <svg className="shell-nav-icon" viewBox="0 0 16 16" aria-hidden="true">
      <path d="M6.7 9.3 9.3 6.7" />
      <path d="M7.6 4.6 9.1 3.1a2.7 2.7 0 0 1 3.8 3.8l-1.5 1.5" />
      <path d="M8.4 11.4l-1.5 1.5a2.7 2.7 0 0 1-3.8-3.8l1.5-1.5" />
    </svg>
  );
}

/* ⛔ `PlusMark` LIVED HERE AND IS DELETED WITH THE THREE BUTTONS THAT DREW IT (wave 24 item 15a,
   ruling R9). It was the flyout footer's plus, used by nothing else — `CreateNewRow` brings its
   own `PlusIcon`, which is private to `NavExtras`. `tsc` named it the moment the last call site
   went (TS6133), which is the argument for a REQUIRED prop and an unused-locals check doing the
   remembering: the CSS twins `.shell-dbfly-make` and `.shell-dbfly-plus` went to zero call sites
   in the same edit and no compiler says a word about those — they are swept by hand below, in
   this session's own index.css region, rather than left as the D-42 residue class. */

/** WAVE 23 R7 — the disclosure caret on the "Database" row: this opens a panel, and the mark
 *  says so before the click does (the same job `ExtIcon` does for a hand-off). */
function CaretIcon() {
  return (
    <svg className="shell-nav-open shell-nav-caret" viewBox="0 0 12 12" aria-hidden="true">
      <path d="M4.4 2.6 8 6l-3.6 3.4" />
    </svg>
  );
}

/** Owner item 11 — the rail toggle: three horizontal bars. One glyph for both rails (the
 *  views rail draws the same geometry), so "minimize a panel" reads as one idea. */
function RailToggleIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 16 16" fill="none" aria-hidden="true">
      <path
        d="M2.5 4.4h11M2.5 8h11M2.5 11.6h11"
        stroke="currentColor"
        strokeWidth="1.35"
        strokeLinecap="round"
      />
    </svg>
  );
}

/**
 * The account corner: ONE line (monogram + name + role, the host's
 * `_account_css` card) that opens a small menu, instead of three buttons
 * crushed into a 236px row — which is what the owner met as "the logout
 * button broke": Sign out wrapped into a 42px two-line stub beside a clipped
 * name. Every action keeps its full label inside the menu.
 */
function AccountMenu({
  user,
  utility,
  onSignOut,
  onSettings,
}: {
  user: SessionUser;
  /** `chrome:'utility'` pages other than the Analyst slot — placed here, where
   *  the host keeps them (Settings in the chrome, not the module list). */
  utility: NavPage[];
  onSignOut: () => void;
  onSettings: (s: SettingsSection) => void;
}) {
  const [open, setOpen] = useState(false);
  const wrap = useRef<HTMLDivElement | null>(null);

  useEffect(() => {
    if (!open) return;
    const onDoc = (e: MouseEvent) => {
      if (wrap.current && !wrap.current.contains(e.target as Node)) setOpen(false);
    };
    const onKey = (e: KeyboardEvent) => {
      if (e.key === "Escape") setOpen(false);
    };
    document.addEventListener("mousedown", onDoc);
    document.addEventListener("keydown", onKey);
    return () => {
      document.removeEventListener("mousedown", onDoc);
      document.removeEventListener("keydown", onKey);
    };
  }, [open]);

  // ⚠ Unicode letter/number, not [a-z0-9]: the app's `_account_css` uses
  // Python's `str.isalnum()`, so an ASCII-only class here would give a
  // non-Latin name an initial in one shell and a blank circle in the other.
  const initial = (user.name.match(/[\p{L}\p{N}]/u)?.[0] ?? "").toUpperCase();
  const extras = utility.filter((p) => p.key !== "analyst");

  return (
    <div className="shell-account-wrap" ref={wrap}>
      {open ? (
        <div className="shell-menu" role="menu">
          {/* ⚠ WAVE 19 R12 SUPERSEDES WAVE 15 R12, IN BOTH HALVES.
              Wave 15 renamed this row "Settings" → "Profile" and kept a second,
              admin-only "Manage users" beside it. The owner has now ruled the
              opposite: ONE row, called **Settings**, with a gear, shown to
              EVERYONE, landing on Account — and admins meet "Manage users" where
              it always really lived, as a tab in the modal's own rail.

              The two rows were the problem, not either label. They opened the
              SAME modal at two different tabs, so the account menu was quietly
              acting as a second navigation for a surface that already has one;
              an admin had to decide which door to use before knowing which tab
              they wanted. Landing everyone on Account and letting the rail do
              the rest removes the decision.

              ⛔ `verify_ui.py`'s naming gate was inverted in the same change
              (its R12 check asserted the wave-15 wording, so it would have gone
              red on the correct edit). Wave-19 amendment 1 in the wave doc. */}
          <button
            type="button"
            className="shell-menu-item"
            role="menuitem"
            onClick={() => {
              setOpen(false);
              onSettings("account");
            }}
          >
            <GearIcon />
            Settings
          </button>
          {extras.length ? <div className="shell-menu-rule" role="separator" /> : null}
          {extras.map((p) => (
            <a
              key={p.key}
              className="shell-menu-item"
              role="menuitem"
              href={appLink(APP_BASE, p.key)}
              target="_blank"
              rel="noreferrer"
              onClick={() => setOpen(false)}
            >
              {/* WAVE 17 ITEM 15b (R8) — the `settings` special-case is GONE.
                  This row used to relabel one registry key on its way to the
                  screen, which is a client deciding what the payload meant. R8
                  deletes the host surface itself, so the honest client change
                  is not to HIDE the key here — hard-coding an exclusion would
                  outlive the thing it excludes — but to stop treating any key
                  specially and let the payload decide. When `nav_pages` stops
                  emitting it, the row stops existing, with nothing here to
                  update. Every utility row now wears its registry label. */}
              {p.label}
              <ExtIcon />
            </a>
          ))}
          <div className="shell-menu-rule" role="separator" />
          <button
            type="button"
            className="shell-menu-item is-signout"
            role="menuitem"
            onClick={() => {
              setOpen(false);
              onSignOut();
            }}
          >
            Sign out
          </button>
        </div>
      ) : null}
      <button
        type="button"
        className="shell-account"
        aria-haspopup="menu"
        aria-expanded={open}
        onClick={() => setOpen((v) => !v)}
      >
        {user.avatar ? (
          // Wave 14 C-AVATAR — the chip wears the photo. Inline-styled: `.shell-avatar`'s
          // stylesheet is another wave-14 session's file (index.css), so the img carries
          // its own fit rules and inherits the span's box from the class.
          <img
            className="shell-avatar"
            src={user.avatar}
            alt=""
            aria-hidden="true"
            style={{ objectFit: "cover", padding: 0 }}
          />
        ) : (
          <span className="shell-avatar" aria-hidden="true">{initial}</span>
        )}
        <span className="shell-account-who">
          <span className="shell-account-name">{user.name}</span>
          <span className="shell-account-role">{isAdmin(user) ? "Admin" : "Member"}</span>
        </span>
        <DotsIcon />
      </button>
    </div>
  );
}

/**
 * ⭐ WAVE 30 (R5) — THE OUTERMOST BOUNDARY, and the ONLY one that can cover the three
 * EARLY RETURNS below (`FormPublic`, the boot card, `LoginPage`) plus this component's own
 * body: its route resolution, its nav shaping and its derivations all run BEFORE any JSX
 * exists to wrap. A throw in any of them used to take the document with it, and a person
 * who cannot get past the login screen has no navigation left to escape with.
 *
 * ⚠ Split rather than nested inline for one reason: a boundary cannot catch a throw from
 * its OWN render. `ErrorBoundary` has to be the parent of the component that fails, so the
 * frame becomes a child and the default export becomes the wrapper.
 */
export default function Shell() {
  return (
    <ErrorBoundary surface="Loopable">
      <ShellFrame />
    </ErrorBoundary>
  );
}

function ShellFrame() {
  const [session, setSession] = useState<Session>({ phase: "checking" });
  const [nav, setNav] = useState<Nav>({ phase: "idle" });
  // Wave 18 (C3-UT): bumped after "+ New database" so the rail refetches and the new ut_ key
  // appears without a reload. Wave 19 (R8/C1) adds the second and only other bumper — a
  // rename or an icon change, for the same reason: the override lives in the SERVER's nav
  // payload, so the rail re-asks rather than the client inventing what the answer will be.
  // Both bumps are "the server changed, ask it again"; nothing may bump this to paint state
  // the server does not hold — the nav stays server-driven.
  const [navEpoch, setNavEpoch] = useState(0);
  const [dataError, setDataError] = useState("");
  const [toast, setToast] = useState("");
  // `null` = closed. The SECTION is the open state, so "Settings" and
  // "Users" are one component reached two ways rather than two dialogs.
  const [settings, setSettings] = useState<SettingsSection | null>(null);
  // ── WAVE 20 items 18/23/26 (R10, C-SHARE): the access editor, for all three kinds ──
  //
  // The dialog is the SHELL's, and it is opened from two places that must not import
  // each other: this frame (a database's ⋯) and the views rail (a view's or folder's
  // ⋯), which is host-neutral `customer-grid/` code. So the rail raises a window event
  // — the same channel the grid already uses for toasts and staleness — and the frame,
  // which owns modals, renders it.
  const [shareFor, setShareFor] = useState<ShareRequest | null>(null);
  // ── WAVE 20 item 25 (C-ALERT): the inbox lives beside the nav, not in it ──────
  //
  // `inbox` is held HERE rather than inside the pane because the badge outlives the
  // pane: the count has to be on screen while the panel is shut, which is the only
  // state in which a badge is useful at all.
  const [inbox, setInbox] = useState<Inbox>(EMPTY_INBOX);
  /** ⭐ W32 (ASK C-17) — the in-flight VIEW_OPEN retry ladder's canceller, if one is running.
   *  A reader who clicks a second notification while the first is still retrying would otherwise
   *  have TWO ladders racing, and the older one would yank them back to the previous view. */
  const viewEmitCancel = useRef<null | (() => void)>(null);
  const route = useHashRoute();
  // WAVE 23 C9 — non-null on `#/form/<token>` only. Computed here rather than inside the render
  // branch because the hash normaliser below has to read it too, and two copies of "is this the
  // public form?" is how one of them ends up answering differently.
  const formToken = formTokenOf(route);
  // ⭐⭐ W33-T26 — the published-view token, read the same way and for the same reason the line
  // above gives: two copies of "is this a public route?" is how one of them ends up answering
  // differently. Both feed the SAME auth-bounce exemption and the same pre-session render branch.
  const publishToken = publishTokenOf(route);
  const publicToken = formToken || publishToken;
  // Owner items 10/11 — the navigation folds to a slim strip: by the toggle in the rail head,
  // or automatically when the user clicks into the work surface (NAV_MINIMIZE_EVENT from the
  // grid). Remembered per browser; expanding is always one click on the same toggle.
  const [navCollapsed, setNavCollapsed] = useState<boolean>(() => {
    try {
      return localStorage.getItem("aios-nav-collapsed") === "1";
    } catch {
      return false;
    }
  });
  useEffect(() => {
    try {
      localStorage.setItem("aios-nav-collapsed", navCollapsed ? "1" : "0");
    } catch {
      // storage can be blocked; the toggle still works for the session
    }
  }, [navCollapsed]);
  // Owner item 3 (2026-07-31) — the collapsed strip names its icons on hover. A real DOM
  // tooltip positioned FIXED beside the rail: the rail scrolls and clips (overflow), so a
  // CSS ::after inside it could never escape; and it is pointer-events:none by standing rule
  // ([[ui-invisible-to-assertions]] — a tooltip that can receive the pointer swallows the
  // next click).
  const [navTip, setNavTip] = useState<{ label: string; y: number } | null>(null);
  useEffect(() => {
    if (!navCollapsed) setNavTip(null);
  }, [navCollapsed]);
  const tipEnter = useCallback(
    (label: string) => (e: ReactMouseEvent<HTMLElement>) => {
      const r = e.currentTarget.getBoundingClientRect();
      setNavTip({ label, y: r.top + r.height / 2 });
    },
    []
  );
  const tipLeave = useCallback(() => setNavTip(null), []);
  // ── WAVE 20 item 7 (R9): the collapsed strip expands from its own BACKGROUND ──
  //
  // Until now the 56px strip had exactly one way back — the logo — and the owner
  // kept clicking the empty space beside an icon, which did nothing at all. R9:
  // "clicking the collapsed strip's blank/background area EXPANDS it; page icons
  // keep navigating directly."
  //
  // ⚠ THE TEST IS THE TARGET, NOT THE CURRENT ELEMENT. `e.currentTarget === e.target`
  // would only fire on the aside's own few pixels of padding — every gap the user
  // actually clicks belongs to `.shell-nav` or `.shell-nav-list`, which are not
  // interactive but ARE elements. So the rule is inverted: a click that landed on
  // (or inside) a control does what that control does; anything else is background.
  // ⛔ `closest` and not a tag check: the click usually lands on the `<svg>` or the
  // `<span>` INSIDE the link, so testing the target's own tagName would treat every
  // icon click as background and swallow the navigation R9 explicitly preserves.
  const expandOnBlank = useCallback((e: ReactMouseEvent<HTMLElement>) => {
    const hit = e.target as Element | null;
    if (hit?.closest?.('a,button,input,textarea,select,[role="menuitem"],[role="dialog"]')) return;
    setNavCollapsed(false);
  }, []);

  // ── WAVE 23 items 9/10 (R7/R8, contract C10): the DATABASE FLYOUT ──────────────────────────
  //
  // R7 takes the databases OUT of the rail: the always-on `.shell-nav-list` band becomes a panel
  // behind a "Database" button, so the rail is a fixed set of destinations instead of a list
  // whose height is a function of how many tables the tenant made.
  //
  // `dbAt` is the anchor rect (null = shut), `dbQuery` the search. The panel renders OUTSIDE the
  // `<aside>` and `position: fixed`, for the same reason `shell-nav-tip` does: the rail scrolls
  // and clips, so anything that must escape it cannot be its descendant.
  const [dbAt, setDbAt] = useState<{ x: number; y: number } | null>(null);
  const [dbQuery, setDbQuery] = useState("");
  const dbPanel = useRef<HTMLDivElement | null>(null);
  const dbButton = useRef<HTMLButtonElement | null>(null);
  const closeDbFly = useCallback(() => {
    setDbAt(null);
    setDbQuery("");
  }, []);
  // ⚠ Declared here and READ inside the close effect below, because that effect must not
  // re-subscribe on every drag state change — and because the guard it needs is "a drag is in
  // flight", which is state this component already holds (`dragKey`, declared further down with
  // the other prefs state). A ref keeps the effect's dependency list honest.
  const draggingRef = useRef(false);

  /**
   * ⛔ THREE WAYS OUT, AND ONE THING THAT MUST NOT CLOSE IT.
   *
   * Out: an outside mousedown, Escape, or a database link (handled at the link — a click on the
   * row's ⋯ must NOT close the panel the menu is anchored inside).
   *
   * NOT out: a DRAG. This panel carries the folder drag-and-drop the rail used to (`NAV_DRAG_TYPE`,
   * the `__root__` drop target, `draggable` rows). A pointer that leaves the panel mid-drag would
   * otherwise trip the outside-click rule and unmount the drop target under the cursor — the
   * folder move silently fails and the panel vanishes, which reads as a crash. The wirings this
   * wave must keep green (W-3/W-5 live on these rows) would still pass, because a gate cannot
   * see a drop that never lands.
   *
   * And NOT the trigger button: without that exemption the mousedown closes the panel and the
   * button's own click immediately reopens it, so the control could never be used to shut the
   * thing it opened. (`useMenu` in NavExtras has this quirk; a rail button is used far more often
   * than a row's ⋯, so it is worth the ref here.)
   */
  useEffect(() => {
    if (!dbAt) return;
    const onDown = (e: MouseEvent) => {
      if (draggingRef.current) return;
      const t = e.target as Node | null;
      if (dbPanel.current?.contains(t as Node)) return;
      if (dbButton.current?.contains(t as Node)) return;
      closeDbFly();
    };
    const onKey = (e: KeyboardEvent) => {
      if (e.key === "Escape") closeDbFly();
    };
    document.addEventListener("mousedown", onDown, true);
    document.addEventListener("keydown", onKey, true);
    return () => {
      document.removeEventListener("mousedown", onDown, true);
      document.removeEventListener("keydown", onKey, true);
    };
  }, [dbAt, closeDbFly]);

  // ── WAVE 23 C10: the recents stamp ────────────────────────────────────────────────────────
  //
  // `opened` mirrors the stamps this session made, so Home shows the database you opened one
  // click ago rather than the state of the world at sign-in (`mergeRecents`' own note). It is
  // NOT persisted: a reload re-asks the server, which is the only end that knows.
  const [opened, setOpened] = useState<Record<string, number>>({});
  const lastStamped = useRef("");

  // The window signals the data layer raises (apiContract.ts). It talks to the
  // frame this way because `customer-grid/**` is host-neutral — the same tree
  // the Streamlit embed ships — and must not import a shell.
  useEffect(() => {
    const onUnauthorized = () => setSession({ phase: "anon" });
    const onDataError = (e: Event) =>
      setDataError(String((e as CustomEvent).detail ?? "") || "The data could not be loaded.");
    const onToast = (e: Event) => setToast(String((e as CustomEvent).detail ?? ""));
    const onNavMinimize = () => setNavCollapsed(true);
    // C-SHARE: the rail asks, the frame opens. A malformed detail opens NOTHING —
    // `parseShareRequest` fail-closes on an unknown kind rather than launching a
    // dialog whose every save would 400.
    const onShareOpen = (e: Event) =>
      setShareFor(parseShareRequest((e as CustomEvent).detail));
    window.addEventListener(UNAUTHORIZED_EVENT, onUnauthorized);
    window.addEventListener(DATA_ERROR_EVENT, onDataError);
    window.addEventListener(TOAST_EVENT, onToast);
    window.addEventListener(NAV_MINIMIZE_EVENT, onNavMinimize);
    window.addEventListener(SHARE_OPEN_EVENT, onShareOpen);
    return () => {
      window.removeEventListener(UNAUTHORIZED_EVENT, onUnauthorized);
      window.removeEventListener(DATA_ERROR_EVENT, onDataError);
      window.removeEventListener(TOAST_EVENT, onToast);
      window.removeEventListener(NAV_MINIMIZE_EVENT, onNavMinimize);
      window.removeEventListener(SHARE_OPEN_EVENT, onShareOpen);
    };
  }, []);

  // The toast clears itself; nothing else depends on it having been seen.
  useEffect(() => {
    if (!toast) return;
    const t = setTimeout(() => setToast(""), 6000);
    return () => clearTimeout(t);
  }, [toast]);

  // DEBT D-38 (wave 22): the error card is ABOUT a surface, so leaving that surface clears
  // it — before this, one failed fetch left the card over every module until sign-out
  // (`setDataError("")` at the nav effect runs only on a WHO change). Clearing on the route
  // commit cannot suppress a real failure: the failing surface raises DATA_ERROR_EVENT from
  // its own fetch, which resolves after this effect has run.
  useEffect(() => {
    setDataError("");
  }, [route]);

  // Boot: ask the server who we are. ⚠ Every boot, no cache — the X3 cookie is
  // HttpOnly and revocable by epoch bump, so the server is the only thing that
  // can answer this and a remembered answer is a stale one.
  useEffect(() => {
    let dead = false;
    void me().then((user) => {
      if (!dead) setSession(user ? { phase: "authed", user } : { phase: "anon" });
    });
    return () => {
      dead = true;
    };
  }, []);

  // Keyed on the USERNAME, not the session object: a new object identity on
  // every state write would re-fetch the nav for no reason.
  const who = session.phase === "authed" ? session.user.username : null;

  useEffect(() => {
    if (who === null) {
      setNav({ phase: "idle" });
      return;
    }
    let dead = false;
    // ⚠ WAVE 19 — STALE-WHILE-REFRESH, and this line is why the icon picker works
    // at all. This effect re-runs on every `navEpoch` bump, and it used to blank
    // the nav to `loading` each time: `entries` reads as `NO_ENTRIES` whenever the
    // phase is not `ready`, so the whole database list unmounted behind a spinner
    // and remounted a round trip later. Every row's `RowMenu` went with it —
    // taking the OPEN icon picker's state with it, so "pick a shape, then pick a
    // tone" was impossible and every click flashed the rail. "+ Create new…"
    // (gated on `ready`) disappeared too.
    //
    // It was invisible before because the only bumper was "+ New database", which
    // navigates away in the same beat. R8 made the bump a frequent, EXPLORATORY
    // action, which is what turned a flash into a broken control.
    //
    // ⛔ SAFE ACROSS ACCOUNTS, which is the only thing that could make it
    // dangerous: an account switch always passes through `anon` (sign-out, or the
    // 401 event), so `who` becomes null, this effect takes the branch above and
    // sets `idle` — a stale nav can never survive into a different session's
    // render. Same stale-while-refresh doctrine the data cache already follows.
    setNav((cur) => (cur.phase === "ready" ? cur : { phase: "loading" }));
    // ⚠ Clear the last session's failures. Without this, a read error survives
    // a sign-out/sign-in and the freshly authenticated user lands on an error
    // panel describing something that happened to somebody else's session.
    setDataError("");
    setToast("");
    void fetchNav().then((r) => {
      if (dead) return;
      if (r.ok) {
        // `chrome:'utility'` rows leave the module list — the payload has said
        // so since X6; the Analyst slot and the account menu place them where
        // the host does (`core.perms.nav_pages`' own contract).
        const { main, utility } = splitChrome(r.pages);
        setNav({ phase: "ready", entries: shapeNav(main, APP_BASE), utility,
                 recents: r.recents,
                 ...(r.empty ? { empty: r.empty } : {}),
                 // ⭐ W31-T11 — carried onto the state, not dropped here. A flag parsed off the
                 // wire and discarded before render is a wiring that goes nowhere, which is
                 // exactly how wave 20 shipped four of them.
                 ...(r.omitted ? { omitted: r.omitted } : {}),
                 ...(r.degraded ? { degraded: r.degraded } : {}) });
      }
      // 401 is not "the nav is broken", it is "the session died under us" —
      // conflating them would leave a signed-out user staring at a frame.
      else if (r.status === 401) setSession({ phase: "anon" });
      else setNav({ phase: "error",
                    ...(r.status === NAV_TIMEOUT_STATUS ? { timedOut: true } : {}) });
    });
    return () => {
      dead = true;
    };
  }, [who, navEpoch]);

  /**
   * ⭐⭐ W33-T22 — RECORD THE RAIL THE PAYLOAD JUST DESCRIBED, for the next first paint.
   *
   * ⚠ IT LIVES UP HERE WITH THE OTHER EFFECTS, NOT BESIDE THE ROWS IT IS ABOUT, and that is not
   * a filing preference: the render body below has several early returns (the public form at
   * `<FormPublic/>`, the boot gate at `session.phase === "checking"`, the login page), so a hook
   * written next to the rail would be called on some renders and not others — the rules-of-hooks
   * crash, and one that only fires on the public-form route.
   *
   * ⛔ ONLY `ready` WRITES. An `error` payload knows nothing about this account's grants, and
   * recording "absent" from a failed read would suppress the placeholder on the next load for a
   * row the user actually has [[empty-answer-vs-unfinished-answer]].
   */
  useEffect(() => {
    if (nav.phase !== "ready") return;
    rememberRail(who, {
      analyst: !!findAnalyst(nav.utility),
      automation: !!findAutomation(nav.entries),
    });
  }, [nav, who]);

  // NO_ENTRIES, not a fresh `[]`: a new array identity on every render would
  // re-run the hash effect below on every render for no reason.
  const entries = nav.phase === "ready" ? nav.entries : NO_ENTRIES;
  // Wave 18: a fresh TENANT (server says `no_databases`) is welcomed, not warned.
  const tenantEmptyState =
    nav.phase === "ready" && entries.length === 0 && nav.empty === "no_databases";

  // ── C-SCHEMA (2026-08-02): per-user folders over the database list + the
  // schema drawer. Placement is cosmetic per-user state — the server-filtered
  // nav still decides what exists; prefs only arrange it.
  const [navPrefs, setNavPrefs] = useState<NavPrefs>(EMPTY_NAV_PREFS);
  const navPrefsRef = useRef(navPrefs);
  navPrefsRef.current = navPrefs;
  const [closedFolders, setClosedFolders] = useState<ReadonlySet<string>>(new Set());
  const [schemaFor, setSchemaFor] = useState<string | null>(null);
  useEffect(() => {
    if (who === null) {
      setNavPrefs(EMPTY_NAV_PREFS);
      setSchemaFor(null);
      return;
    }
    let dead = false;
    void fetchNavPrefs().then((p) => {
      if (!dead) setNavPrefs(p);
    });
    return () => {
      dead = true;
    };
  }, [who]);
  // Optimistic with an honest revert: the rail moves now; a refused write puts
  // it back and says so rather than leaving a lie on screen.
  const commitPrefs = useCallback((next: NavPrefs) => {
    const prev = navPrefsRef.current;
    setNavPrefs(next);
    void saveNavPrefs(next).then((ok) => {
      if (!ok) {
        setNavPrefs(prev);
        setToast("The folder change was not saved — the store refused the write.");
      }
    });
  }, []);
  const movePage = useCallback(
    (key: string, folderId: string | null) => {
      const cur = navPrefsRef.current;
      const placement = { ...cur.placement };
      if (folderId) placement[key] = folderId;
      else delete placement[key];
      commitPrefs({ folders: cur.folders, placement });
    },
    [commitPrefs]
  );
  const renameFolder = useCallback(
    (id: string, name: string) => {
      const cur = navPrefsRef.current;
      commitPrefs({
        folders: cur.folders.map((f) => (f.id === id ? { ...f, name } : f)),
        placement: cur.placement,
      });
    },
    [commitPrefs]
  );
  const deleteFolder = useCallback(
    (id: string) => {
      const cur = navPrefsRef.current;
      commitPrefs({
        folders: cur.folders.filter((f) => f.id !== id),
        placement: Object.fromEntries(
          Object.entries(cur.placement).filter(([, v]) => v !== id)
        ),
      });
    },
    [commitPrefs]
  );
  const toggleFolder = useCallback((id: string) => {
    setClosedFolders((prev) => {
      const next = new Set(prev);
      if (next.has(id)) next.delete(id);
      else next.add(id);
      return next;
    });
  }, []);
  // ── Wave 14 C-NAVFOLD (items 4/6): drag replaces the menu's Move-to-folder. A PRIVATE
  // dataTransfer MIME so a drop anywhere text-editable types nothing (the wave-13 C-LAYOUT
  // scar); `dropTarget` is a folder id or "__root__" (drag out = drop on the list itself).
  const [dragKey, setDragKey] = useState<string | null>(null);
  const [dropTarget, setDropTarget] = useState<string | null>(null);
  // WAVE 23 C10 — read by the flyout's outside-click rule, which must NOT fire mid-drag (see
  // its note). Assigned during render like `navPrefsRef` above: the effect keeps a stable
  // dependency list and still sees the current answer.
  draggingRef.current = dragKey !== null;
  const createFolder = useCallback(
    (name: string) => {
      const cur = navPrefsRef.current;
      if (cur.folders.length >= MAX_NAV_FOLDERS) {
        setToast(`At most ${MAX_NAV_FOLDERS} folders.`);
        return;
      }
      const id = `nf_${Date.now().toString(36)}${Math.floor(Math.random() * 1e6).toString(36)}`;
      commitPrefs({ folders: [...cur.folders, { id, name }], placement: cur.placement });
      // ⭐ WAVE 23 C10 — SHOW THE THING THAT WAS JUST MADE. "+ Create new…" stayed in the RAIL
      // while the folders it creates moved into the FLYOUT, so naming a folder produced no
      // visible result at all: the only surface that draws one was a closed panel. The
      // affordance and its effect ended up in different places, which is the class of defect
      // this rework was supposed to remove rather than introduce. Opening the panel is the
      // smaller of the two fixes and keeps C10's rail order exactly as ruled.
      const at = flyoutFrom(dbButton.current);
      if (at) setDbAt(at);
    },
    [commitPrefs]
  );

  // ── WAVE 19 R8 / C1: the tenant-wide name + icon overrides (`nav_meta`) ──────
  //
  // ⚠ NOT OPTIMISTIC, unlike `commitPrefs` two blocks up, and the asymmetry is
  // the point. Prefs are this user's own arrangement held in this component's
  // state, so the rail can move now and revert if the write is refused.
  // `nav_meta` is TENANT-WIDE and lives in the SERVER's nav payload — the shell
  // holds no copy to update. Painting a new name locally would mean rendering a
  // label from one source while every other reader of the nav still had the old
  // one; re-asking is one cheap round trip and it cannot disagree with itself.
  // ── C-ALERT: the unread count, and the door that MAKES an alert ───────────────
  //
  // Polled once per session boot and after every write this frame knows about —
  // never on a timer. A nav badge that re-fetches every 30 seconds is a background
  // request per user per minute for a number nobody is looking at; the honest
  // refresh points are "the app just started" and "you just did something".
  useEffect(() => {
    if (who === null) {
      setInbox(EMPTY_INBOX);
      return;
    }
    let dead = false;
    const pull = () => {
      void fetchInbox().then((r) => {
        if (!dead && r.ok) setInbox(r.value);
      });
    };
    pull();
    // ...and again when the tab is looked at, which is the honest substitute for a
    // timer: news arrives while you are elsewhere, and "elsewhere" is exactly when a
    // poll would be wasted. One request per return to the tab, none while it sits.
    window.addEventListener("focus", pull);
    return () => {
      dead = true;
      window.removeEventListener("focus", pull);
    };
  }, [who]);

  // The rail asks for an alert on a view; the FRAME answers, because the rail does
  // not know its own topic — it holds views, and the scope key is the route's.
  useEffect(() => {
    const onCreate = (e: Event) => {
      const req = parseAlertCreate((e as CustomEvent).detail);
      if (!req) return;
      // ⛔ THE GRID'S OWN SCOPE, NOT THE HASH (2026-08-14). This used to map the route key
      // inline — a third copy of `gridScopeFor`, and one the Query module breaks outright:
      // a grid mounted at `#/query` would have filed every alert raised from it against
      // `customer`, because "query" is not a database key and the else-branch is the
      // customer topic. Silently wrong, on a door that answers 200. `currentSurfaceScope()`
      // is the value the emitting grid stamps on all its other events, read back.
      const topic = currentSurfaceScope();
      void createAlert(req.viewId, topic, req.label).then((r) => {
        if (!r.ok) {
          // ⚠ The 400 `no_filter` is a real answer and rides through verbatim: a
          // view with no active filter matches everything, so an alert on it could
          // never see an entrant. "Refused, and here is why" beats a dead bell.
          setToast(r.message);
          return;
        }
        setToast(`Alerting on "${req.label}". New records that enter it appear under Alerts.`);
        void fetchInbox().then((got) => {
          if (got.ok) setInbox(got.value);
        });
      });
    };
    window.addEventListener(ALERT_CREATE_EVENT, onCreate);
    return () => window.removeEventListener(ALERT_CREATE_EVENT, onCreate);
  }, []);

  const commitNavMeta = useCallback(async (key: string, patch: NavMetaPatch) => {
    const ok = await saveNavMeta(key, patch);
    if (ok) setNavEpoch((e) => e + 1);
    else setToast("That change was not saved — the store refused the write.");
  }, []);

  /**
   * ⭐ WAVE 21 item 6 (R3, contract C3) — delete a user database, and then leave.
   *
   * The confirm face owns the QUESTION; this owns the round trip and the two
   * things that have to happen after a yes:
   *
   *   · the nav is refetched (`navEpoch`), because the row must go — and because
   *     the server is the only end that knows what else went with it;
   *   · if the deleted table is the one on screen, the route moves. The hash
   *     would otherwise still name a key the payload no longer carries, and
   *     `resolveRoute` answers that with a blank main pane — a shell that looks
   *     broken as the reward for a successful delete.
   *
   * The route change is deliberately NOT optimistic. It fires after the server
   * confirms, so a refused delete leaves the user exactly where they were, still
   * looking at the table they asked about.
   */
  const removeDatabase = useCallback(
    async (key: string): Promise<{ ok: boolean; error?: string }> => {
      const r = await deleteTable(key);
      if (!r.ok) return r;
      // The grid's cached rows for THIS table die with it: a remount inside the
      // cache window would otherwise re-paint a table that no longer exists.
      clearCustomersCache();
      setNavEpoch((e) => e + 1);
      setToast("Database deleted.");
      // An EMPTY hash, not a computed one: `resolveRoute` answers "" with
      // `defaultRoute(entries)`, so the landing surface is chosen by the same
      // rule a fresh sign-in uses — and it is chosen from the REFETCHED nav,
      // which a key computed here (from the list still holding the dead row)
      // could not be.
      if (route === key) window.location.hash = "";
      return { ok: true };
    },
    [route]
  );

  // Keep the URL honest in both directions: an anonymous shell sits on
  // `#/login`, and a signed-in one never does.
  //
  // ⭐ WAVE 23 C10 — THE LANDING MOVED, AND ALL THREE SITES MOVED TOGETHER. `LANDING_PREFERENCE`
  // and `defaultRoute` are the other two (nav.ts); this is the redirect a fresh sign-in takes.
  // C10's own warning is that a half-move strands logins on a dead hash, so:
  //
  //   · the `entries.length` gate is GONE. It existed because `defaultRoute([])` was `""` — a
  //     redirect to `#/` — so the frame had to wait for the nav before it could name a landing.
  //     `home` is chrome and needs no entry, so there is nothing left to wait for, and the
  //     tenant whose nav is legitimately empty (a fresh workspace, wave 18) now lands somewhere
  //     real instead of sitting on the login hash until a database exists.
  //   · an EMPTY hash normalises to the landing too. `removeDatabase` sets `hash = ""` after a
  //     delete and relies on this; before, an empty hash silently rendered `customer_data` while
  //     the URL said nothing.
  useEffect(() => {
    // ⛔ WAVE 23 C9 — THE PUBLIC FORM IS EXEMPT FROM BOTH DIRECTIONS. Without the first
    // exemption an anonymous visitor at `#/form/<token>` is bounced to `#/login` before the
    // render branch is ever reached, and the public door is public only to people who already
    // have an account. Without the second, a SIGNED-IN person testing their own form link is
    // yanked to Home mid-read.
    // ⭐⭐ W33-T26 — `publicToken`, not `formToken`. Wave 33's published view (`#/v/<token>`) needs
    // BOTH exemptions for exactly the reasons the paragraph above gives about the form, and
    // extending the existing test is the only way they cannot come apart: a second `if` here
    // would be a second answer to "is this route public", and the wave-23 note is about what
    // happens when one of two such answers is forgotten.
    if (publicToken) return;
    if (session.phase === "anon" && route !== LOGIN_ROUTE) {
      window.location.hash = `#/${LOGIN_ROUTE}`;
    } else if (session.phase === "authed" && (route === LOGIN_ROUTE || route === "")) {
      window.location.hash = `#/${defaultRoute(entries)}`;
    }
  }, [session.phase, route, entries, publicToken]);

  // ── WAVE 24 item 13 (R10, wiring W24-W3): Home's automations ────────────────────────────
  //
  // ⚠ FETCHED HERE, NOT IN `HomePage`. Home holds no state of its own by contract — its whole
  // C10 argument for being CHROME rather than a granted surface is that it draws only what the
  // frame already has. A fetch inside it would make it a surface with a data contract.
  //
  // ⛔ A 403 BECOMES `[]`, NOT AN ERROR. An account without the automation grant is not a
  // failure — it is an account that has no automations to show, and the section simply does not
  // render. Raising DATA_ERROR_EVENT here would put an error card over Home for every member of
  // a tenant whose automations they were never granted.
  //
  // ⚠ RE-ASKED ON `navEpoch`, so Home does not go stale behind a write it did not make: creating
  // or deleting a database bumps the nav, and a deleted database's automations are paused and
  // re-stamped by the same route (C3's footprint contract), so their tiles have to be re-read.
  // ⚠ WAVE 25 (R8): this used to say `navEpoch` "is what makes create an automated database
  // land". That door is deleted, and the epoch bump has never been what refreshed THIS list
  // anyway — `createAndOpen` happens on the automation surface, which reloads its own list.
  const [autoTiles, setAutoTiles] = useState<AutomationTile[]>([]);
  useEffect(() => {
    if (who === null) {
      setAutoTiles([]);
      return;
    }
    const ac = new AbortController();
    let dead = false;
    void listAutomations(ac.signal)
      .then((r) => {
        if (dead) return;
        setAutoTiles(
          (r.automations || []).map((a) => ({
            id: a.id,
            name: a.name,
            /* ⭐ WAVE 26 · ITEM 18 (R14) — `state: stateOf(a)` is GONE with Home's status dot.
               `AutomationTile` dropped the field, so leaving the call here would be a computed
               fact with no reader. `stateOf` itself stays exported and alive in `automationApi`
               (the automation module still decides "is this running" for its own surfaces) — this
               is one CONSUMER leaving, not the definition. */
            // The rail's own second line, one fact not two: the forward-looking one when a
            // schedule exists (it answers "does this run itself?"), the last run otherwise.
            sub: a.schedule?.enabled
              ? a.nextRunAt
                ? `Next ${a.nextRunAt}`
                : "Scheduled"
              : a.status?.lastRunAt
                ? `Last run ${a.status.lastRunAt.replace("T", " ").slice(0, 16)}`
                : "Manual only",
          }))
        );
      })
      .catch(() => {
        if (!dead) setAutoTiles([]);
      });
    return () => {
      dead = true;
      ac.abort();
    };
  }, [who, navEpoch]);

  // WAVE 23 C10 — stamp the route as opened, for Home's recents.
  //
  // ⚠ ABOVE THE EARLY RETURNS with every other hook (the React #310 scar at the block below),
  // so it re-resolves the route itself rather than reading the `active` computed after them.
  //
  // THREE THINGS IT DELIBERATELY DOES NOT STAMP: a chrome route (Home and Connectors resolve to
  // no entry, so `hit` is undefined); a route the nav has not answered for yet (same reason —
  // `entries` is empty in flight, and stamping an unresolved key would record a page that may
  // not exist); and a hand-off, which opens the current application in another tab and is not a
  // surface this shell can put a recents tile back into.
  //
  // `lastStamped` suppresses the REPEAT write a `navEpoch` bump would otherwise cause (new
  // `entries` identity, same route) — and clears whenever the route resolves to nothing, so
  // leaving a table and coming back to it does re-stamp, which is what makes the ordering on
  // Home mean "most recently opened".
  useEffect(() => {
    if (session.phase !== "authed") return;
    const hit = resolveRoute(entries, route);
    if (!hit || hit.kind !== "native") {
      lastStamped.current = "";
      return;
    }
    if (lastStamped.current === hit.key) return;
    lastStamped.current = hit.key;
    postOpened(hit.key);
    setOpened((cur) => ({ ...cur, [hit.key]: Math.floor(Date.now() / 1000) }));
  }, [session.phase, route, entries]);

  const signOut = useCallback(() => {
    // The cached customer payload dies with the session: the next sign-in on
    // this browser may be a different account, and a cached book crossing that
    // boundary would be the cross-user leak EXIT-3b exists to prevent.
    clearCustomersCache();
    void logout().then(() => setSession({ phase: "anon" }));
  }, []);

  // ── Wave 18 hooks — ⛔ ABOVE the early returns, or they run conditionally. The first
  // version of this block sat below the `anon` return and blanked the whole app with React
  // error #310 on the first authed render (found by SESSION B's probe, booked in the wave
  // doc): the anon render mounted N hooks, the authed render mounted N+5, and React refuses
  // a component whose hook count changes between renders. Every hook in this component stays
  // above `if (session.phase …) return`, whatever lands here next wave.
  // (owner item 3): the assistant's under-construction note.
  // ⭐ WAVE 24 item 14 — it carries WHICH boarded door was knocked on, not just "open". Two
  // surfaces are now under construction (the assistant, and Home's templates card) and they are
  // the same dialog with a different sentence — a second near-identical modal would be the
  // "variety is a defect" failure, and a shared one that could not say which door you came
  // through would tell a reader about the wrong feature.
  /** ⭐ 2026-08-14 — `"assistant"` LEFT THIS UNION. The assistant is a route now, so the only
   *  boarded door left behind this state is Templates. Narrowing the type rather than leaving the
   *  dead member is what makes `setAssistOpen("assistant")` a compile error instead of a screen
   *  nobody meant to be reachable. */
  const [assistOpen, setAssistOpen] = useState<false | "templates">(false);
  // ⛔ ESCAPE CLOSES A MODAL, or its scrim becomes a trap. The assistant note shipped with only
  // a scrim-click and a Close button, and the first close-out probe to press Escape found every
  // subsequent click swallowed by an invisible full-screen div — the
  // painted-but-unclickable failure [[ui-invisible-to-assertions]] names, in reverse. The
  // new-database dialog had Escape only while its INPUT held focus, which is not the same thing.
  useEffect(() => {
    if (!assistOpen && !newDbOpenRef.current) return;
    const onKey = (e: KeyboardEvent) => {
      if (e.key !== "Escape") return;
      setAssistOpen(false);
      setNewDb((cur) => (cur && cur.busy ? cur : null));
    };
    window.addEventListener("keydown", onKey);
    return () => window.removeEventListener("keydown", onKey);
  });
  // (C3-UT): "+ New database" + the user-table Add-record bar.
  //
  // WAVE 23 C10 — the dialog grew a `mode`: blank, or from a template.
  //
  // ⭐ WAVE 25 (R8) — IT WAS A THREE-WAY CHOICE AND THE THIRD ANSWER IS DELETED. The chooser's
  // third row ("Automated") never selected a mode at all: it closed the dialog and handed off to
  // the automation surface, which is why the union has only ever had two members. So this type is
  // unchanged and the ROW is what goes — the tell that the third option was never really a way of
  // creating a database, which is exactly what R8 rules.
  const [newDb, setNewDb] = useState<null | {
    mode: "blank" | "template";
    name: string;
    busy: boolean;
    err: string;
  }>(null);
  const newDbOpenRef = useRef(false);
  newDbOpenRef.current = newDb !== null;
  const openNewDb = useCallback((mode: "blank" | "template") => {
    setNewDb({ mode, name: "", busy: false, err: "" });
  }, []);
  /*
   * ⛔ `openAutomated` STOOD HERE AND IS DELETED WITH ITS THREE DOORS (wave 25 item 5a, R8).
   *
   * It closed the dialog, routed to `#/automation` and signalled `AUTOMATION_CREATE_EVENT` — and
   * it was that event's ONLY signaller, which is why the constant and its listener go in the same
   * change (see the tombstones in `apiContract.ts` and `AutomationSurface.tsx`). Leaving either
   * side behind rebuilds the wave-24 defect from the opposite end.
   */
  /**
   * ⭐ WAVE-27 item 19 (owner ruling R15) — WHAT A HAND-MADE DATABASE STARTS WITH.
   *
   * `user_tables.create()` mints exactly ONE column (`Name`) and zero rows, so a new database
   * opened as a single blank column with nothing in it — a surface with no shape to copy. R15
   * seeds four columns and three blank records instead.
   *
   * ⛔ IT LIVES AT THIS DOOR, NOT IN `create()`, AND THAT IS THE RULING'S OWN SCOPE. R15 is
   * "hand-created databases only; preset/automation spawns untouched", and `source` cannot
   * express that: MEASURED, `automation_engine.py:1983` mints a database for the automation
   * builder's "+ New database" through the same `create()` with the DEFAULT source, i.e. `Blank`.
   * Seeding inside `create()` would therefore put four columns and three empty rows in front of
   * every automation target as well — and `_vestigial_name_field` (the wave-26 migration) is
   * written against `create()` minting EXACTLY ONE column, so it would start reading the seed as
   * somebody's work. This dialog is the only door a person names a database at.
   *
   * ⛔ `status` SHIPS WITH ITS OPTIONS. A select declaring none is the W26 item-24 defect
   * verbatim — `if ([])` is truthy, so a panel hands back an empty list as an ANSWER and the
   * filter reads as dead — and `aios_grid` separately degrades an option-less select to text on
   * read, so the column would not even stay a select.
   *
   * ⛔ `name` DECLARES `pinned`. D-80 is exactly this key going unwritten: the primary column
   * resolves as `fields.find(f => f.pinned) ?? fields[0]`, and because nothing ever set the flag,
   * "whichever column was created first" WAS the rule. With four columns arriving at once,
   * leaving it implicit stops being harmless.
   */
  const SEED_FIELDS = [
    { key: "name", label: "Name", type: "text", pinned: true },
    { key: "status", label: "Status", type: "select",
      options: ["Todo", "In progress", "Done"] },
    { key: "assignee", label: "Assignee", type: "user" },
    { key: "date", label: "Date", type: "date" },
  ];
  const SEED_ROWS = 3;
  const createDb = useCallback(async () => {
    setNewDb((cur) => {
      if (!cur || cur.busy || !cur.name.trim()) return cur;
      const name = cur.name;
      void (async () => {
        try {
          // WAVE 23 C10 — `source` rides the body the route ALREADY forwards
          // (`routes_tables.py:192` passes it to `user_tables.create`). It is the literal
          // `"Blank"` because that is the enum member the server accepts; ⚠ an unknown source is
          // SILENTLY DOWNGRADED to Blank there (user_tables.py:165), so a third literal invented
          // here would create a table that quietly disagrees with the word the dialog used.
          // ⚠ "Automated" is not one of these values and never was. The engine stamps that source
          // itself when an automation spawns its own target — which is now the ONLY way a
          // database becomes automated, R8 having deleted the doors that implied otherwise.
          const res = await fetch(`${API_V1}/tables`, {
            method: "POST",
            credentials: CREDENTIALS,
            headers: { "Content-Type": "application/json" },
            // R15's four columns ride the SAME body the route already forwards to
            // `user_tables.create(fields=...)` — no new endpoint, no server change.
            body: JSON.stringify({ label: name.trim(), source: "Blank", fields: SEED_FIELDS }),
          });
          const body = (await res.json().catch(() => null)) as
            | { key?: string; error?: { message?: string } }
            | null;
          if (!res.ok || !body?.key) {
            setNewDb({ mode: "blank", name, busy: false,
                       err: body?.error?.message || `The server answered ${res.status}.` });
            return;
          }
          // R15's three blank records, through the ORDINARY row door the grid's own "+" uses.
          //
          // ⚠ SEQUENTIAL, not `Promise.all`: three concurrent writes race the same store
          // document, and the last read-modify-write would win with two rows lost.
          //
          // ⚠ FAILURE HERE DOES NOT FAIL THE CREATE, and that asymmetry is deliberate. The
          // database and its four columns already exist; reporting "could not create it" over a
          // missing blank row would be false, and rolling the database back would destroy the
          // part that worked. A database that opens with two blank rows instead of three is not
          // a state anybody can be harmed by — the grid's "+" adds the third.
          for (let i = 0; i < SEED_ROWS; i += 1) {
            try {
              await fetch(`${API_V1}/tables/${body.key}/rows`, {
                method: "POST",
                credentials: CREDENTIALS,
                headers: { "Content-Type": "application/json" },
                body: JSON.stringify({ values: {} }),
              });
            } catch {
              break;      // the store is unreachable; the next two would fail the same way
            }
          }
          setNewDb(null);
          setNavEpoch((e) => e + 1);
          window.location.hash = `#/${body.key}`;
        } catch {
          setNewDb({ mode: "blank", name, busy: false, err: "Cannot reach the server." });
        }
      })();
      return { ...cur, busy: true, err: "" };
    });
  }, []);
  // ⛔ `addRecord` LIVED HERE AND IS DELETED WITH THE BAR THAT CALLED IT (wave 20 item 4,
  // R8 / C-ADDROW). The shell was POSTing `/tables/{key}/rows` itself, clearing the grid's
  // cache and firing ROWS_STALE_EVENT to make the new row appear — a write path owned by
  // the frame, for a surface the grid owns. R8 moves the affordance into the grid as a
  // trailing "+" row (S3's half), where the row it adds is the row you are looking at, so
  // the shell stops being a second writer of table data.

  // ⭐ WAVE 23 C9 (SESSION D's page, E's mount — wiring W23-W2) — THE PUBLIC FORM, BEFORE THE
  // AUTH WALL.
  //
  // ⛔ THE POSITION IS THE ENTIRE CONTRACT. It sits above BOTH early returns: above `anon`,
  // obviously, but also above `checking` — a person filling in a public form should not watch a
  // brand mark while `me()` resolves a session they do not have. It is below every hook, which
  // is the other half of the rule (the React #310 scar the block at :828 documents): the hook
  // count may not change between renders, and this branch would be the shortest possible path
  // to breaking that.
  //
  // ⚠ THE SMALLEST POSSIBLE BRANCH, deliberately (C9's own words). It reads a token out of the
  // hash and renders D's page; it does not fetch, does not touch the session, does not import
  // anything of the grid's. Nothing else in this frame is reachable from it.
  //
  // ⛔ AND THE HASH NORMALISER HAS TO KNOW. The effect at :812 pins an anonymous shell to
  // `#/login` — which would have bounced every anonymous form visitor to a login screen before
  // this branch ever rendered. `isPublicForm` is read there too; a mount without that exemption
  // is a public door that only signed-in people can reach.
  //
  // ⚠ The SERVER side of this is genuinely public (D's `routes_forms.py`, the automation-hook
  // pattern — uniform 403, constant-time compare). This branch adds no new public SURFACE: the
  // SPA bundle is already served unauthenticated (main.py:257-295, `_DEV_FIXTURES` guard), so
  // `#/form/<token>` has always loaded for free. What it adds is a client route that renders
  // something there instead of the login page.
  if (formToken) {
    return <FormPublic token={formToken} />;
  }

  // ⭐⭐ W33-T26 (item 8b, R5) — THE PUBLISHED VIEW, on the same seam and by the same argument as
  // the form above: this branch adds no new public SURFACE. The SPA bundle is already served
  // unauthenticated, so `#/v/<token>` has always loaded for free; what this adds is a client
  // route that renders something there instead of the login page. The genuinely public half is
  // the server's (`routes_publish.py` — one uniform 403, constant-time compare, a streamed body
  // bound, a per-IP sliding window).
  // ⚠ It returns BEFORE the boot gate below, so a stranger never sees the shell's brand card
  // flash while `/me` decides they are nobody.
  if (publishToken) {
    return <PublishedView token={publishToken} />;
  }

  if (session.phase === "checking") {
    // Deliberately wordless. A "Loading…" line here would flash for one round
    // trip on every load, and the mark says everything the moment needs.
    return (
      <div className="shell-boot">
        <Brand size={44} className="login-brand" />
      </div>
    );
  }

  if (session.phase === "anon") {
    return (
      <LoginPage
        onSignedIn={(user) => {
          // Same rule as sign-out, from the other side: a fresh session never
          // reads the previous session's cached rows.
          clearCustomersCache();
          setSession({ phase: "authed", user });
        }}
      />
    );
  }

  const active = resolveRoute(entries, route);
  const utility = nav.phase === "ready" ? nav.utility : NO_UTILITY;
  const analyst = findAnalyst(utility);
  // ── WAVE 19 R10 / C3: Automation LEAVES THE DATABASE LIST ────────────────────
  //
  // Strategy A, chosen at the grill: a CLIENT-SIDE relocation. The registry row,
  // `NATIVE_KEYS`, the API payload and the `#/automation` render branch below are
  // all untouched — Automation is still a granted surface the server decides on,
  // it simply stops being drawn among the databases, because it is not one.
  //
  // ⚠ THE FILTER FEEDS `foldNav`, IT IS NOT APPLIED INSIDE THE `.map()`, and the
  // difference is a bug you would find weeks later. `foldNav` counts a folder's
  // members from `prefs.placement`, so a user who had already dragged Automation
  // into a folder would get a folder head reading "1" with nothing underneath it
  // — the count derived from a list that still had the row, the rows drawn from
  // one that did not.
  //
  // ⛔ AND `entries` STAYS WHOLE. `resolveRoute`, `active`, `defaultRoute`, the
  // empty-nav note and `tenantEmptyState` all read it: filtering there would
  // break the hash route this button navigates to, and would tell a tenant whose
  // only granted surface is Automation that it has no surfaces at all.
  //
  // ⭐ WAVE 25 (D-54) — THE FILTER IS NO LONGER WRITTEN HERE. It was
  // `entries.filter(e => e.key !== "automation")`, i.e. a local expression every consumer had to
  // remember, and Home did not (it drew the Automation surface a tile under "Databases"). The
  // split is a PROPERTY of the row now (`shapeNav` stamps `surface`) and `databaseEntries` is the
  // one accessor — which also returns the BRANDED `DatabaseEntry[]`, so handing a database
  // surface the raw `entries` is a compile error rather than one extra tile nobody looks at.
  const automation = findAutomation(entries);
  /**
   * ⭐⭐ W31-T11 (owner item 6b) — WHAT TO DRAW WHERE AUTOMATION GOES WHEN IT IS NOT THERE.
   *
   * ⛔ THE DEFECT, in one line: `{automation ? … : null}` renders **literally nothing** for
   * three completely different situations, and the reader cannot tell them apart:
   *   1. `/nav` is in flight — `entries` is `NO_ENTRIES` until `phase === "ready"`, so the rail
   *      shows its four static rows and a complete-looking gap. `/nav` measured a **9.5–14.0 s
   *      band** on tenant #0, and `reference/ERROR 5.png` is exactly this screen. The owner read
   *      it as the module disappearing, and reported it across several waves.
   *   2. the payload came back and this workspace's catalogue does not include the module —
   *      deliberate, and the rail should stay quiet.
   *   3. the payload came back INCOMPLETE (`degraded`) or never came back at all — not
   *      deliberate, and silence is a lie about what exists.
   * ⚠ ONLY CASE 2 DRAWS NOTHING. The other two get the slot, so an absence is never mistaken for
   * a workspace that simply does not have the feature. (The rail already had a region-level
   * spinner and error line four rows below — far enough away that nothing connected them to this
   * gap, which is why "there is a loading state" was true and did not help.)
   */
  /**
   * ⭐⭐ W33-T22 (owner item 1, "I ask you fix this in multiple different waves already") —
   * THE RULE ABOVE IS NOW A FUNCTION, BECAUSE IT HAD TO APPLY TO A SECOND ROW.
   *
   * ⛔ THE MECHANISM IS A RENDER GATE, NOT A DURATION, and that is why two shipped LATENCY fixes
   * did not touch the symptom. `/nav` was 11.0 s (wave 30) and is 26 ms (wave 32) — the rail still
   * painted twice, because `:1437` releases the shell as soon as `/me` resolves and `:911` makes
   * `entries` `NO_ENTRIES` until `nav.phase === "ready"`. First paint therefore happens while the
   * answer to "does this workspace have Automation / an Analyst?" is still unknown, at ANY speed.
   *
   * ⛔ TWO SYMPTOMS, ONE CAUSE, and the second one is what the owner's words actually describe.
   * W31-T11 gave AUTOMATION the four-state slot below, so that row stopped vanishing. It left
   * the AI-assistant row at `{analyst ? … : null}` with NO placeholder — and that row is ABOVE
   * Query / Inbox / Automation / Database / **Connectors**. So when `/nav` landed it INJECTED a
   * ~34 px row and pushed all five down a beat after first paint. Connectors (`:1765`) has no
   * gate of any kind and cannot arrive late: it MOVES. "Automation and Connection module still
   * loads separately" is one late row and one shoved row, from the same missing placeholder.
   *
   * ⚠ ONE FUNCTION, TWO CALLERS, ON PURPOSE. The four states were a hand-written ternary chain
   * on one row; a second copy is how the two rows start disagreeing about what `degraded` means
   * [[one-question-two-normalizers]]. `present` is the ONLY per-row input.
   *
   * ⛔ WHAT THIS DOES NOT CLAIM. `silent` still collapses the slot, and it must: reserving space
   * for a surface the server did not grant is a hard-coded row this frame refuses to have
   * (see the file header). So an account that lacks Automation or the Analyst grant still sees
   * ONE reflow when `/nav` lands — down from every account seeing one, every load.
   */
  type RailSlot = "row" | "pending" | "unavailable" | "silent";
  const railWas = railMemory(who);
  const railSlot = (present: boolean, remembered: string): RailSlot =>
    present
      ? "row"
      : nav.phase === "loading" || nav.phase === "idle"
        ? // ⭐ THE MEMORY, and it only ever SUPPRESSES. `false` means "this account did not have
          // this row last time", which is the one case where reserving a slot creates the flash
          // -then-collapse a reviewer caught in the first version of this fix. Unknown, or any
          // other value, reserves — see `railMemory`'s note on why unknown is not false.
          railWas[remembered] === false
          ? "silent"
          : "pending"
        : nav.phase === "error"
          ? "unavailable"
          : nav.phase === "ready" && (nav.degraded?.length ?? 0) > 0
            ? "unavailable"
            : "silent";
  const automationSlot: RailSlot = railSlot(!!automation, "automation");
  const analystSlot: RailSlot = railSlot(!!analyst, "analyst");
  const dbEntries = databaseEntries(entries);
  // WAVE 23 C10 — the flyout's search. A plain label substring, case-folded: this list is at
  // most a few dozen rows, so anything cleverer (fuzzy, ranked) would be a scoring function
  // nobody can predict over a set small enough to read.
  //
  // ⚠ SEARCHING RENDERS FLAT. `foldNav` is called with EMPTY prefs while a query is live,
  // because a folder head whose members were filtered out would report a count it is not
  // showing — the same "count derived from one list, rows from another" defect the R10
  // relocation note two blocks up already documents.
  const dbQ = dbQuery.trim().toLowerCase();
  const shownEntries = dbQ
    ? dbEntries.filter((e) => e.label.toLowerCase().includes(dbQ))
    : dbEntries;
  // WAVE 23 C10 — what Home draws: the server's recents plus this session's own stamps.
  const recents = mergeRecents(nav.phase === "ready" ? nav.recents : NO_RECENTS, opened);

  return (
    <div className="shell-root">
      <aside
        className={"shell-side" + (navCollapsed ? " is-collapsed" : "")}
        // Item 7 (R9) — background click expands. Bound only while collapsed, so the
        // open rail is exactly what it was; the accessible route stays the labelled
        // brand button below ("Expand navigation"), which is what a keyboard reaches.
        onClick={navCollapsed ? expandOnBlank : undefined}
      >
        {/* The PRODUCT brand — the same mark the Streamlit host paints, from the
            same generated file, so the two shells cannot drift. "Royal Imports"
            stays on business documents only. */}
        <div className="shell-side-head">
          {/* Owner item 2 (2026-07-31) — collapsed, the LOGO is the way back and the
              three-bars toggle disappears (CSS hides it). One stable element in both states
              so the mark can animate rather than swap; disabled while expanded, where it is
              brand, not control. */}
          <button
            type="button"
            className="shell-brand-btn"
            disabled={!navCollapsed}
            aria-label={navCollapsed ? "Expand navigation" : undefined}
            onMouseEnter={navCollapsed ? tipEnter("Expand navigation") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
            onClick={() => setNavCollapsed(false)}
          >
            <Brand size={26} className="shell-brand" />
          </button>
          <button
            type="button"
            className="shell-rail-toggle"
            aria-label="Minimize navigation"
            aria-expanded={!navCollapsed}
            title="Minimize navigation"
            onClick={() => setNavCollapsed(true)}
          >
            <RailToggleIcon />
          </button>
        </div>

        <nav className="shell-nav">
          {/* ⭐ WAVE 23 item 9 (R7, contract C10) — HOME, the new landing, at the top of the rail.
              An `<a>` to a CHROME route: it needs no grant because it renders nothing the server
              did not already send (nav.ts' `CHROME_ROUTES` note carries the full argument, and
              the :1039 law below is unchanged — an undeclared SURFACE is still denied). */}
          <a
            className={"shell-nav-item shell-nav-home" + (route === HOME_ROUTE ? " is-active" : "")}
            href={`#/${HOME_ROUTE}`}
            onMouseEnter={navCollapsed ? tipEnter("Home") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
          >
            <HomeIcon />
            <span className="shell-nav-label">Home</span>
          </a>

          {/* The Analyst slot, above the database list — the host's own IA
              (app.py:8166 pins "AI assistant" over the nav tree, same label,
              same sparkle). Wave 18 (owner item 3): the hand-off into Streamlit
              is PAUSED — the click opens an in-app "under construction" note
              instead. The nav item, the registry row and the Streamlit Analyst
              page all stay (kept-not-ported, never delete); only the door is
              boarded until a later wave expands it. */}
          {analyst ? (
            /* ⭐⭐ 2026-08-14 (owner item 2) — THE DOOR IS OPEN. Owner: *"you can unblock user
               from accessing the AI assistant, in staging only so that we can see if the prompt
               to query data works."* It used to open `setAssistOpen("assistant")` — an
               under-construction note for the Streamlit Analyst that was DELETED at EXIT-6, so
               the row led to an apology for a surface that is never coming back.
               ⛔ STILL A `<button>`, NOT AN `<a>`, and that is deliberate rather than lazy. This
               row's box is W33-T22 — the owner's own layout-jump report — and its three arms
               (`analyst` / `pending` / `unavailable`) have to stay the same 34 px. `<a>` and
               `<button>` do measure identically here (wave 19 R11's reset, measured on staging
               v12), so this is belt not braces: changing the element is a risk with no return
               when a hash write does the same job. */
            <button
              type="button"
              className={
                "shell-nav-item shell-nav-assist" +
                (route === ASSISTANT_ROUTE ? " is-active" : "")
              }
              onClick={() => {
                window.location.hash = `#/${ASSISTANT_ROUTE}`;
              }}
              onMouseEnter={navCollapsed ? tipEnter("AI assistant") : undefined}
              onMouseLeave={navCollapsed ? tipLeave : undefined}
            >
              <SparkIcon />
              <span className="shell-nav-label">AI assistant</span>
            </button>
          ) : analystSlot === "pending" ? (
            /* ⭐⭐ W33-T22 (owner item 1) — THE ASSISTANT'S OWN SLOT, held from first paint.
               ⛔ THIS IS THE ROW THE OWNER WAS ACTUALLY REPORTING. Without it, `/nav` landing
               INSERTED ~34 px here and pushed Query / Inbox / Automation / Database / Connectors
               down — so the row a reader sees "load separately" is the one with NO gate at all
               (Connectors, `:1765`), which cannot arrive late and therefore must have MOVED.
               ⚠ Same classes as Automation's pending arm on purpose: `.shell-nav-item.is-pending`
               and `.shell-nav-item.is-pending .lp-spin{16px}` are GENERIC rules in index.css, and
               `.shell-nav-assist` applies by class, so this placeholder is the same 34 px box the
               real row will be. A new modifier class would need an index.css rule (B's file, C4)
               and would render at a different height until it got one — which is the jump again. */
            <div
              className="shell-nav-item shell-nav-assist is-pending"
              aria-busy="true"
              aria-label="AI assistant is loading"
            >
              <span className="lp-spin" aria-hidden="true" />
              <span className="shell-nav-label shell-nav-label--muted">AI assistant</span>
            </div>
          ) : analystSlot === "unavailable" ? (
            /* ⛔ The payload never came, or came back `degraded`. Silence here is a claim that this
               workspace has no assistant, and we do not know that — same argument as W31-T11's
               unavailable arm one row below, same `title`, same quiet dot. */
            <div
              className="shell-nav-item shell-nav-assist is-unavailable"
              title={
                nav.phase === "error" && nav.timedOut
                  ? "The navigation request timed out. Reload to retry."
                  : "This list could not be loaded in full. Reload to retry."
              }
            >
              <SparkIcon />
              <span className="shell-nav-label shell-nav-label--muted">AI assistant</span>
              <span className="shell-nav-note-dot" aria-hidden="true" />
            </div>
          ) : null}

          {/* ⛔ THE "AI agent" ROW WAS HERE AND IS DELETED (owner, 2026-08-14): *"AI assistant
              module IS AI agent module. So no need to separate it like that."* Wave 33's own note
              on this row had already argued the collapse and deferred it as ASK C-9 because
              W33-T22's done-when named the seven rail rows; the owner has now ruled, so the set
              goes back to those seven. `verify_wiring.py` asserts the absence rather than merely
              dropping the check that asserted the presence — a deleted check is
              [[gate-can-report-green-on-nothing]]. */}

          {/* ⭐⭐ W32-T05 (item 7, ruling R1) — QUERY, directly under the AI assistant because that is
              what it IS: the place the assistant's work goes. R1 — "every AI-built view lands under
              the Query module".
              ⚠ THE OWNER'S SIX-ROW ORDER IS UNCHANGED ABOVE AND BELOW IT (Home / AI assistant /
              Inbox / Automation / Database / Connectors, wave 24 item 1). Query is a SEVENTH row,
              inserted beside its own producer rather than appended — appending would have put the
              newest surface furthest from the thing that fills it, and re-ordering the six would
              have re-opened a decision the owner already made. */}
          <a
            className={"shell-nav-item shell-nav-query" + (route === QUERY_ROUTE ? " is-active" : "")}
            href={`#/${QUERY_ROUTE}`}
            onMouseEnter={navCollapsed ? tipEnter("Query") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
          >
            {/* ⭐ 2026-08-14 (owner item 2) — A MAGNIFIER, not the sparkle. Verbatim: *"Change
                the icon for Query, it should just be a magnifying glass icon"*. The sparkle now
                appears exactly once in the rail, on the row that actually is the AI. */}
            <SearchIcon />
            <span className="shell-nav-label">Query</span>
          </a>

          {/* WAVE 20 item 25 (C-ALERT) — "Alerts".
              ⭐ WAVE 24 item 1 — IT MOVED UP, above Automation. The owner's order is
              Home / AI assistant / Alerts / Automation / Database / Connectors, and the
              two pairs that swapped are Alerts↔Automation here and Database↔Connectors
              below. Nothing else about these rows changed: MEASURED on staging v12, all
              six already render 13.8125px / w500 / Inter / rgb(32,36,51), `<a>` and
              `<button>` alike (wave 19 R11's reset holding). The one row in this band
              that differed was "+ Create new…" (12.75px / w400 / muted), and item 15a
              takes it out of the rail entirely — see `CreateNewRow`'s own note.
              ⭐⭐ W32-T04 (owner item 16, ruling R7) — IT IS A NAV LINK NOW, AND THE
              PARAGRAPH THIS REPLACES WAS RIGHT ON ITS PREMISE AND WRONG ON ITS
              CONCLUSION. Its premise — the nav is server-filtered and an undeclared
              surface is denied — still holds and is why Inbox is CHROME rather than a
              `registry.py` module (see `nav.INBOX_ROUTE`: a registry key outside a
              tenant's `modules` list is silently omitted in every tenant). Its
              conclusion, that the surface must therefore be a PANEL, does not follow:
              Home and Connectors are routes under the same law, because a chrome route
              renders nothing the server did not already grant — and `GET /notifications`
              is this account's own notifications, composed by the server, for this
              session. The owner asked for an inbox that reads like email; a dropdown
              that closes when you look away is the one shape that cannot. */}
          <a
            className={"shell-nav-item shell-nav-alerts" + (route === INBOX_ROUTE ? " is-active" : "")}
            href={`#/${INBOX_ROUTE}`}
            onMouseEnter={navCollapsed ? tipEnter("Inbox") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
          >
            <BellIcon />
            <span className="shell-nav-label">Inbox</span>
            {badgeText(inbox.unread) ? (
              <span
                className="shell-nav-badge"
                // Not aria-hidden: the count IS the information, and a badge a screen
                // reader cannot see makes the row read as an empty inbox.
                aria-label={`${inbox.unread} unread`}
              >
                {badgeText(inbox.unread)}
              </span>
            ) : null}
          </a>

          {/* WAVE 19 R10 / C3 — Automation. An `<a>` to the route it already had: the
              surface, its rail and its editor are another session's tree this wave and
              are not touched by any of this. The LABEL comes off the payload, never a
              literal here — the registry owns what this surface is called, and a client
              that hard-codes the word is the drift that outlives the row. */}
          {automation ? (
            <a
              className={
                "shell-nav-item shell-nav-auto" +
                (active && active.key === automation.key ? " is-active" : "")
              }
              href={automation.href}
              onMouseEnter={navCollapsed ? tipEnter(automation.label) : undefined}
              onMouseLeave={navCollapsed ? tipLeave : undefined}
            >
              {/* ⚠ R8 lists Automation among the databases that get an icon
                  ("Customer/Product/Automation/custom"); R10 moves it out of the
                  list where the ⋯ that SETS one lives. So it DISPLAYS a chosen
                  mark — the store and the route already accept `automation` as a
                  key — while the entry point to choose one is the open question
                  booked as amendment 6 for the integrator. Rendering the default
                  glyph unconditionally would have made this the one database
                  that could never show an icon, which is the half of R8 a client
                  has no business deciding. */}
              {automation.icon ? (
                <span className="shell-nav-mark" aria-hidden="true">
                  <FolderMark icon={automation.icon} size={16} />
                </span>
              ) : (
                <AutoIcon />
              )}
              <span className="shell-nav-label">{automation.label}</span>
            </a>
          ) : automationSlot === "pending" ? (
            /* ⭐ W31-T11 — THE PENDING STATE, IN AUTOMATION'S OWN SLOT. The shared spinner mark
               (R6: the mark, never the word "Loading…", which `verify_icons` enforces), on a row
               that occupies the space the real one will. `aria-busy` is what makes it a pending
               ROW to a screen reader rather than a decorative glyph. */
            <div
              className="shell-nav-item shell-nav-auto is-pending"
              aria-busy="true"
              aria-label="Automation is loading"
            >
              <span className="lp-spin" aria-hidden="true" />
              <span className="shell-nav-label shell-nav-label--muted">Automation</span>
            </div>
          ) : automationSlot === "unavailable" ? (
            /* ⛔ W31-T11 — NOT LOADING, AND NOT ABSENT-ON-PURPOSE: the server said this payload
               is incomplete (`degraded`), or it never answered. The row states that rather than
               leaving a gap the reader has to interpret — which is the whole of owner item 6b. */
            <div
              className="shell-nav-item shell-nav-auto is-unavailable"
              title={
                nav.phase === "error" && nav.timedOut
                  ? "The navigation request timed out. Reload to retry."
                  : "This list could not be loaded in full. Reload to retry."
              }
            >
              <AutoIcon />
              <span className="shell-nav-label shell-nav-label--muted">Automation</span>
              <span className="shell-nav-note-dot" aria-hidden="true" />
            </div>
          ) : null}

          {/* ⭐ WAVE 23 item 9 (R7) — THE DATABASE BUTTON, and the end of the always-on band.
              R7: "databases LEAVE the always-on rail; a 'Database' nav button opens the flyout".
              The rail is now a fixed set of destinations whose height does not depend on how many
              tables the tenant made — which is the actual complaint behind the ruling.
              ⛔ A BUTTON, NOT A ROUTE, and for the same reason Alerts is one (:1039): there is no
              `#/databases` surface and inventing one would be the hard-coded page this frame
              refuses to have. It opens a panel over the list the server already sent. */}
          <button
            type="button"
            ref={dbButton}
            className={"shell-nav-item shell-nav-db" + (dbAt ? " is-active" : "")}
            aria-haspopup="dialog"
            aria-expanded={!!dbAt}
            onMouseEnter={navCollapsed ? tipEnter("Database") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
            onClick={(e) => {
              if (dbAt) {
                closeDbFly();
                return;
              }
              const at = flyoutFrom(e.currentTarget);
              if (at) setDbAt(at);
            }}
          >
            <DbIcon />
            <span className="shell-nav-label">Database</span>
            <CaretIcon />
          </button>

          {/* ⭐ WAVE 23 item 10 (R8, contract C11, wiring W23-W3) — CONNECTORS.
              ⭐ WAVE 24 item 1 — it moved BELOW Database. R8 put it above; the owner's wave-24
              order puts the two destinations that open panels-over-server-data (Database, then
              Connectors) at the foot of the rail. A chrome route like Home: the DIRECTORY it
              renders is composed by the server and session-gated, so this row can no more invent
              a connector than Home can invent a database. */}
          <a
            className={
              "shell-nav-item shell-nav-connectors" +
              (route === CONNECTORS_ROUTE ? " is-active" : "")
            }
            href={`#/${CONNECTORS_ROUTE}`}
            onMouseEnter={navCollapsed ? tipEnter("Connectors") : undefined}
            onMouseLeave={navCollapsed ? tipLeave : undefined}
          >
            <PlugIcon />
            <span className="shell-nav-label">Connectors</span>
          </a>

          {/* ⛔ "+ Create new…" IS NO LONGER A RAIL ROW (item 15a, ruling R9). It moved into the
              Database flyout's footer, where the things it creates actually live — and where the
              three `.shell-dbfly-make` buttons used to be. See the footer below, and
              `CreateNewRow`'s own note for why this is also item 1's fix rather than a separate
              cosmetic change: it was the one row in this band whose type differed. */}

          {/* ── THE DATABASE FLYOUT (C10) ────────────────────────────────────────────────────
              ⛔ PORTALLED TO `<body>`, and it has to be. Left inside the `<aside>` it would be a
              descendant of `.shell-side.is-collapsed`, whose rules hide `.shell-nav-label`,
              `.shell-nav-badge` and `.shell-nav-open` — so with the rail folded the panel would
              render a column of unlabelled icons, which is the one state this control exists to
              rescue the user from. `createPortal` is already this tree's answer for exactly this
              (OverlaySurface, CatalogView); the panel is not part of the rail, it only points at
              it. */}
          {dbAt
            ? createPortal(
                <div
                  className="shell-dbfly"
                  ref={dbPanel}
                  role="dialog"
                  aria-label="Databases"
                  style={{ left: dbAt.x, top: dbAt.y }}
                >
                  <div className="shell-dbfly-head">
                    <input
                      autoFocus
                      className="shell-dbfly-search"
                      placeholder="Search databases"
                      value={dbQuery}
                      maxLength={60}
                      onChange={(e) => setDbQuery(e.target.value)}
                      onKeyDown={(e) => {
                        if (e.key === "Escape") closeDbFly();
                      }}
                    />
                  </div>
                  <div
            className={
              "shell-nav-list" + (dropTarget === "__root__" ? " is-drop-root" : "")
            }
            onDragOver={(e) => {
              if (!e.dataTransfer.types.includes(NAV_DRAG_TYPE)) return;
              e.preventDefault();
              e.dataTransfer.dropEffect = "move";
              setDropTarget("__root__");
            }}
            onDragLeave={(e) => {
              if (e.currentTarget.contains(e.relatedTarget as Node)) return;
              setDropTarget(null);
            }}
            onDrop={(e) => {
              const key = e.dataTransfer.getData(NAV_DRAG_TYPE);
              setDropTarget(null);
              setDragKey(null);
              if (!key) return;
              e.preventDefault();
              movePage(key, null);
            }}
          >
            {/* C-SCHEMA: the list folds under the user's folders.
                ⭐ WAVE 23 C10 — the `navCollapsed ? EMPTY_NAV_PREFS :` gate is GONE with the band
                it belonged to. It existed because the 44px strip had no room for folder chrome;
                this panel is 268px wide whatever the rail is doing, so the folders always render
                and the reason for the gate no longer exists. A SEARCH still flattens (see
                `shownEntries`) — that is a different fact about a different state. */}
            {foldNav(shownEntries, dbQ ? EMPTY_NAV_PREFS : navPrefs, closedFolders).map(
              (row) => {
                if (row.kind === "folder") {
                  return (
                    <FolderHead
                      key={`folder:${row.folder.id}`}
                      folder={row.folder}
                      count={row.count}
                      open={row.open}
                      // WAVE 23 C10 — always false in the flyout: the panel has full width in
                      // either rail state, so folder chrome is never the thing being squeezed.
                      collapsed={false}
                      onToggle={() => toggleFolder(row.folder.id)}
                      onRename={(name) => renameFolder(row.folder.id, name)}
                      onDelete={() => deleteFolder(row.folder.id)}
                      isDrop={dropTarget === row.folder.id}
                      dropProps={{
                        onDragOver: (e) => {
                          if (!e.dataTransfer.types.includes(NAV_DRAG_TYPE)) return;
                          e.preventDefault();
                          e.stopPropagation();
                          e.dataTransfer.dropEffect = "move";
                          setDropTarget(row.folder.id);
                        },
                        onDrop: (e) => {
                          const key = e.dataTransfer.getData(NAV_DRAG_TYPE);
                          setDropTarget(null);
                          setDragKey(null);
                          if (!key) return;
                          e.preventDefault();
                          e.stopPropagation();
                          movePage(key, row.folder.id);
                        },
                      }}
                    />
                  );
                }
                const item = row.entry;
                // Wave 17 item 12 — ONE answer, read by the row AND the link.
                // The row paints the tint (so it reaches under the ⋯, matching
                // the Views rail); the link keeps the class because the weight
                // and the full-strength icon hang off `.shell-nav-item.is-active`.
                const isActive = !!active && active.key === item.key;
                const cls =
                  "shell-nav-item" +
                  (item.depth > 0 ? " is-child" : "") +
                  (isActive ? " is-active" : "");
                const inner = (
                  <>
                    {/* WAVE 19 R8 — the tenant's chosen mark, or the cylinder.
                        ⚠ `FolderMark` paints its OWN pastel fill and `-deep`
                        stroke, so it must not wear `.shell-nav-icon` (which sets
                        `stroke: currentColor` and dims to 0.55 — that rule would
                        repaint a deliberately-coloured glyph in the row's ink and
                        then half-erase it). The wrapper span carries only the
                        box, which is why the class is the shell's own and not the
                        grid's `.cg-folder-mark`: that one belongs to another
                        session's CSS region this wave. */}
                    {item.icon ? (
                      <span className="shell-nav-mark" aria-hidden="true">
                        <FolderMark icon={item.icon} size={16} />
                      </span>
                    ) : (
                      <DbIcon />
                    )}
                    <span className="shell-nav-label">{item.label}</span>
                    {/* ⭐ WAVE 27 item 3 (contract C9) — A LOCKED DATABASE SAYS SO HERE.
                        The nav flyout is the only place every database is listed, so it is
                        where the fact belongs — you learn it before you open the thing and
                        go looking for a "+" that will not be there.

                        ⚠ THE TITLE NAMES **WHICH** LOCK, and that is a standing rule rather
                        than politeness: ONE `LockMark` glyph carries all three of the owner's
                        locks (locked database / pre-set field / locked view — DESIGN.md §4),
                        so a bare padlock says only "something here is restricted". This one
                        means records, and it says the half that STAYS OPEN in the same breath,
                        because "locked" reads as read-only and fields are not. */}
                    {item.locked ? (
                      <span
                        className="shell-nav-lock"
                        title="Locked database — records are added by an automation. You can still add and edit fields."
                      >
                        <LockMark size={11} />
                      </span>
                    ) : null}
                    {/* A hand-off opens the current application in a new tab; the
                        arrow declares that before the click finds out. */}
                    {item.kind === "handoff" ? <ExtIcon /> : null}
                    {/* Wave 14 item 6: the "Odoo" provenance badge is GONE — the schema
                        drawer still names the source for whoever asks. */}
                  </>
                );
                if (item.kind === "group") {
                  // A registry family head is not a destination — the app has no
                  // page for it either. A label, never a link.
                  return (
                    <div key={item.key} className="shell-nav-group">
                      {inner}
                    </div>
                  );
                }
                // ⭐ WAVE 23 C10 — the collapsed-rail hover tip is GONE from these rows, with
                // the band it belonged to. It named a database whose LABEL was hidden at 44px;
                // inside the flyout the label is always on screen, so the tip would have been a
                // second copy of the word beside itself. `tipEnter`/`tipLeave` still serve the
                // rail's own rows above.
                //
                // Clicking a database CLOSES the panel: you asked for it, you got it. The
                // handler is on the LINK and not on the list, deliberately — a click on the
                // row's ⋯ must leave the panel open, because that menu is anchored inside it.
                const link =
                  item.kind === "native" ? (
                    <a className={cls} href={item.href} onClick={closeDbFly}>
                      {inner}
                    </a>
                  ) : (
                    <a
                      className={cls}
                      href={item.href}
                      target="_blank"
                      rel="noreferrer"
                      onClick={closeDbFly}
                    >
                      {inner}
                    </a>
                  );
                // The three-dots rides TOP-LEVEL rows in the open rail only —
                // children move with their family, and the folded rail has no
                // horizontal room for a second control.
                return (
                  <div
                    key={item.key}
                    className={
                      "shell-nav-row" +
                      (isActive ? " is-active" : "") +
                      (row.folderId ? " is-foldered" : "") +
                      (dragKey === item.key ? " is-dragging" : "")
                    }
                    // WAVE 23 C10 — `!navCollapsed &&` dropped from both gates below: the panel
                    // is the same width in either rail state, so the two things that gate
                    // referred to (no horizontal room for a ⋯, no room to drag) are no longer
                    // true. The folder-reorder drag and the row menu therefore keep working with
                    // the rail folded, which is the state a user who opened this panel is most
                    // likely to be in.
                    draggable={item.depth === 0}
                    onDragStart={(e) => {
                      e.dataTransfer.setData(NAV_DRAG_TYPE, item.key);
                      e.dataTransfer.effectAllowed = "move";
                      setDragKey(item.key);
                    }}
                    onDragEnd={() => {
                      setDragKey(null);
                      setDropTarget(null);
                    }}
                  >
                    {link}
                    {item.depth === 0 && (
                      <RowMenu
                        entryLabel={item.label}
                        canSchema
                        onSchema={() => setSchemaFor(item.key)}
                        // ── WAVE 19 R8 / C1, walled by R14 ──────────────────
                        // RENAME is `ut_*` only: a built-in label is a compiled
                        // registry literal, and renaming one would leave the nav
                        // and every other reader of `core/registry.py` calling
                        // the same module two different things. ICONS ride every
                        // database — that half of R8 is explicitly "ALL".
                        //
                        // ⛔ WHO MAY IS THE SERVER'S ANSWER, NOT A ROLE CHECK
                        // HERE. R14 put the `ut_` half on `user_tables.may_open`
                        // — the table's CREATOR or a tenant admin — and this
                        // client cannot see who created a user table. So the nav
                        // payload carries `manage` per row and the rail simply
                        // obeys it. Absent reads as NO (fail-closed), and
                        // `POST /nav/meta` re-checks regardless: this is the
                        // courtesy half of "the client hides, the server
                        // forbids", the same one `reachableSection` pays in
                        // Settings. An earlier build gated on `isAdmin` here and
                        // was wrong in the direction that matters — it hid a
                        // control from the person who owned the thing.
                        canRename={!!item.manage && item.key.startsWith("ut_")}
                        onRename={(name) => void commitNavMeta(item.key, { name })}
                        canIcon={!!item.manage}
                        {...(item.icon ? { icon: item.icon } : {})}
                        onIcon={(icon: FolderIcon) =>
                          void commitNavMeta(item.key, { icon })
                        }
                        onIconClear={() => void commitNavMeta(item.key, { icon: null })}
                        // WAVE 20 item 18 (R10) — share THIS database. Offered on the
                        // user's own tables only: `customer_data` and `product_data` are
                        // registry surfaces whose reach is the permission wall's answer,
                        // not one person's to grant ([[aios-permission-wall]]), and a
                        // dialog that recorded a grant the module gate would then ignore
                        // is the "shared, silently inert" failure in reverse.
                        {...(item.key.startsWith("ut_")
                          ? {
                              onShare: () =>
                                setShareFor({
                                  kind: "database",
                                  id: item.key,
                                  label: item.label,
                                }),
                            }
                          : {})}
                        // ⭐ WAVE 21 item 6 (R3, C3, wiring W-5) — THE MOUNT.
                        //
                        // `canDelete` is the SERVER's answer and a REQUIRED prop, so
                        // this expression not being here is a compile error rather
                        // than a feature that quietly does not exist (wave 20's
                        // lesson, written into the type — see RowMenu's own note).
                        //
                        // ⛔ NOT `manage`, and the difference is the whole ruling.
                        // `manage` rides `may_open`, which R14/D-32 widened to
                        // everyone the table is SHARED with; R3 puts delete on the
                        // creator or an admin alone, and refuses it outright for
                        // connector-backed databases. Two questions, two flags.
                        canDelete={!!item.canDelete}
                        onLoadFootprint={() => fetchTableFootprint(item.key)}
                        onDelete={() => removeDatabase(item.key)}
                      />
                    )}
                  </div>
                );
              }
            )}
                    {/* The panel's own empty state: ONE line, and it is different from "this
                        workspace has none" — a search that matched nothing is not a workspace
                        with nothing in it, and saying the second when the first is true is how a
                        reader concludes their data is gone. */}
                    {shownEntries.length === 0 ? (
                      <p className="shell-dbfly-empty">
                        {dbQuery ? "No database matches that." : "No databases yet."}
                      </p>
                    ) : null}
                  </div>
                  {/* ── the create footer ─────────────────────────────────────────────────
                      ⭐ WAVE 24 item 15a (ruling R9, wiring W24-W4) — ONE CONTROL, THE CREATE
                      DOORS. C10's three `.shell-dbfly-make` buttons are deleted and
                      "+ Create new…" moves here from the rail, carrying New database ·
                      From a template · New folder.

                      ⭐ WAVE 25 item 5a (R8) — IT WAS FOUR DOORS AND IS NOW THREE. "Automated
                      database" is deleted here, on Home, and in the New-database dialog. Making
                      an automation is not a way of making a database, and a menu that offered it
                      beside "New database" said it was.

                      ⚠ NOTHING THE THREE BUTTONS OPENED IS LOST, and that was the constraint:
                      blank and template still open the same New-database dialog with the choice
                      pre-selected — and FOLDERS, which the rail row owned and the three buttons
                      never offered, keep their only creation door.

                      ⚠ EACH DOOR CLOSES THE PANEL FIRST, exactly as the buttons did. `New
                      folder` is the one that must NOT: it opens an inline naming form inside
                      this footer, and `createFolder` re-opens the panel so the new folder is
                      visible (C10's own fix for an affordance whose effect was invisible).
                      `CreateNewRow` keeps that form internal, so closing here would unmount the
                      thing the user is typing into. */}
                  <div className="shell-dbfly-foot">
                    <CreateNewRow
                      collapsed={navCollapsed}
                      onExpand={() => setNavCollapsed(false)}
                      onCreateFolder={createFolder}
                      onNewDatabase={() => {
                        closeDbFly();
                        openNewDb("blank");
                      }}
                      onFromTemplate={() => {
                        closeDbFly();
                        openNewDb("template");
                      }}
                      canFolder={entries.length > 0}
                    />
                  </div>
                </div>,
                document.body
              )
            : null}
          {/* Wave 17 item 3 (R6) — the mark, never the word. "Loading…" under an
              empty rail told the reader what they could already see, and it read
              as a nav ITEM for the beat before it vanished. */}
          {nav.phase === "loading" ? (
            <div className="shell-nav-note is-spin">
              <span className="lp-spin" role="status" aria-label="Loading" />
            </div>
          ) : null}
          {/* Honest, and it names the fix. Inventing a nav here would show
              surfaces the server never granted. */}
          {nav.phase === "error" ? (
            <div className="shell-nav-note">
              {nav.timedOut
                ? /* ⭐ W31-T11 — A DEADLINE IS A DIFFERENT FACT FROM A DEAD SERVER, and it earns
                     its own sentence: before this ticket `fetchNav` had no timeout at all, so
                     this state was UNREACHABLE and the rail waited for ever. */
                  "Navigation took too long to load. Reload to retry."
                : "Navigation unavailable. Reload to retry."}
            </div>
          ) : null}
          {/* ⛔ W31-T11 — A 200 THAT COULD NOT READ THE DATABASES SAYS SO. This is the case that
              had no surface at all: the server swallowed a store failure, answered 200 with every
              `ut_*` row missing, and the rail drew a confident, complete-looking list of nothing.
              It is NOT `phase: "error"` — the registry rows are real and usable — so it renders
              beside them rather than replacing them. */}
          {nav.phase === "ready" && (nav.degraded?.length ?? 0) > 0 ? (
            <div className="shell-nav-note">
              Some databases could not be loaded. Reload to retry.
            </div>
          ) : null}
          {/* ⚠ Wave 18: this line is for a MISCONFIGURED ACCOUNT — one whose grants give it
              nothing — and it must not fire for a freshly provisioned TENANT, which has no
              modules by design and is being welcomed on Home. Both at once said "something is
              wrong here" and "welcome, start here" in one screen (caught in the close-out
              visual pass, not by any gate). "+ Create new…" above is the honest affordance in
              the tenant case. */}
          {nav.phase === "ready" && entries.length === 0 && !tenantEmptyState ? (
            <div className="shell-nav-note">No surfaces are available to this account.</div>
          ) : null}
        </nav>

        <div
          className="shell-side-bottom"
          // Collapsed, the 56px strip cannot hold the account POPOVER — so the row's one
          // honest behaviour is "expand me first". Capture-phase, so the menu never opens
          // half-clipped behind the grid.
          onClickCapture={
            navCollapsed
              ? (e) => {
                  e.preventDefault();
                  e.stopPropagation();
                  setNavCollapsed(false);
                }
              : undefined
          }
          onMouseEnter={navCollapsed ? tipEnter(session.user.name) : undefined}
          onMouseLeave={navCollapsed ? tipLeave : undefined}
        >
          <AccountMenu
            user={session.user}
            utility={utility}
            onSignOut={signOut}
            onSettings={setSettings}
          />
        </div>
      </aside>

      {/* Item 3 — the collapsed rail's hover tip: fixed beside the strip, outside the
          scrolling rail that would clip it, and pointer-transparent by standing rule. */}
      {navTip ? (
        <div
          className="shell-nav-tip"
          style={{ top: navTip.y }}
          role="tooltip"
          aria-hidden="true"
        >
          {navTip.label}
        </div>
      ) : null}

      <main className="shell-main">
        {/* ⭐ WAVE 30 (R5) — THE CONTENT-AREA BOUNDARY, and the reason it is HERE and not around
            the whole shell: the `<aside>` rail is its SIBLING, so a surface that throws leaves the
            navigation mounted and the user can walk away from the broken page instead of reloading
            a blank document. That is the difference the ticket's done-when is naming.
            ⚠ `key={route}` is load-bearing. A boundary LATCHES — once it holds an error it renders
            the panel until it is remounted — so without the key, navigating away from a failing
            database would carry its failure card onto every page afterwards. */}
        <ErrorBoundary key={route} surface={active?.label ?? "This page"}>
        {/* ⚠ An honest failure, never a fallback to the bundled sample. Behind
            a login, plausible-looking sample revenue is fabricated data on a
            screen the user has every reason to trust. */}
        {dataError && active?.kind === "native" ? (
          <div className="shell-placeholder">
            <h1>{active.label}</h1>
            <p>{dataError}</p>
            <button className="login-submit shell-retry" type="button" onClick={() => window.location.reload()}>
              Retry
            </button>
          </div>
        ) : active?.kind === "native" && ENVELOPE_KEYS.has(active.key) ? (
          // EXIT wave 2 — a Y1-envelope page. The KEY is the only thing that
          // varies: wave 3's Collections and Procurement come through this same
          // branch, which is the whole return on the envelope contract.
          <PageSurface key={active.key} pageKey={active.key} label={active.label} />
        ) : active?.kind === "native" && active.key === "automation" ? (
          // Wave 18 (C-AUTONAV): the Automation surface — its OWN secondary rail + editor,
          // props-free by contract (it fetches /api/v1/automations itself). SESSION D's tree.
          //
          // ⭐ WAVE 23 C13 (owner item 2), wiring W23-W1 — THE SAME FRAME AS EVERY DATABASE.
          //
          // This branch used to mount the surface BARE: no `shell-db-frame`, no `DbHead`. So
          // the one page in the product that is not a database was also the one page whose
          // name was drawn by its own component, at its own size and weight — three title
          // treatments (the surface's 16px/700 editable input, its 20px/600 empty-state h1,
          // and the frame's 16px/650 `shell-db-name`) against the grid's one. The fix is not
          // to restyle the stand-in but to delete the reason it exists: one title system,
          // owned by the shell, mounted here.
          //
          // ⚠ THE LABEL COMES OFF THE PAYLOAD, exactly as the rail's does (:1006). C13 words
          // it "label 'Automation'" and that IS `active.label` — the registry's literal, or a
          // tenant's `nav_meta` override of it. Hard-coding the word here would put the same
          // surface's name in two places and let them drift on the day someone renames it.
          //
          // ⛔ THE HEIGHT CHAIN. `.auto-surface` is `height: 100%`, so dropping it straight
          // into the frame's flex column would size it against the WHOLE frame and push its
          // rail a header's height below the fold. `.shell-auto-host` is the same `flex: 1 1
          // auto; min-height: 0` link `.shell-grid-host` is for glide — and it is the shell's
          // OWN class rather than a `.shell-db-frame > .auto-surface` rule, because
          // `.auto-*` is SESSION B's CSS region this wave and a frame has no business
          // reaching into its child's namespace to make itself fit.
          <div className="shell-db-frame">
            <DbHead
              label={active.label}
              glyph={<AutoIcon />}
              {...(active.icon ? { icon: active.icon } : {})}
            />
            <div className="shell-auto-host">
              <Lazily surface="Automation"><AutomationSurface /></Lazily>
            </div>
          </div>
        ) : active?.kind === "native" ? (
          // The native grid surfaces — ONE component, topic decided by the route. Wave 16:
          // the `#/cohort` route left with the cohort registry row (cohorts are LOCKED VIEWS
          // in the Customer rail, C-LOCK; `scope=cohort` stays a working server surface for
          // stored artifacts), and `#/product_data` arrived (C-TOPIC) — the same tree over
          // the SKU catalogue. The `key` forces a remount on a route change so one topic's
          // view state never bleeds into the other's. Wave 18 (C3-UT): a `ut_` route is a
          // USER TABLE through the same tree — scope IS the key — with the shell-owned
          // Add-record bar above it (the doc's amendment: zero CustomerGrid edits).
          // WAVE 20 item 4 (R8): ONE frame for every database. The old branch gave user
          // tables a header-plus-grid frame and the built-ins a bare grid, which is why
          // Customer and Product had nowhere to put a name.
          <div className="shell-db-frame">
            <DbHead
              label={active.label}
              {...(active.icon ? { icon: active.icon } : {})}
            />
            <div className="shell-grid-host">
              <OverlayProvider>
                {/* ⭐ 2026-08-14 — `gridScopeFor` (shell/dbFrame.tsx), not the inline ternary that
                    stood here. Identical answers; the difference is that the Query module needs
                    the SAME map, and the two spellings (registry key vs grid scope) fail SILENTLY
                    when they diverge — `CustomerGrid`'s VIEW_OPEN listener drops an event whose
                    `topic` is the other one. [[one-question-two-normalizers]] */}
                <CustomerGrid key={active.key} scope={gridScopeFor(active.key)} />
              </OverlayProvider>
            </div>
          </div>
        ) : active ? (
          <StranglerPage entry={active} />
        ) : route === CONNECTORS_ROUTE ? (
          // ⭐ WAVE 23 item 10 (R8, C11, wiring W23-W3) — the connectors directory.
          //
          // The one action the page cannot perform itself: a `manage: "keychain"` row opens
          // Settings on the Keychains tab, and the Settings MODAL is the frame's. Same division
          // as every other panel here — the page knows what it wants, the frame owns the door.
          <Lazily surface="Connectors"><ConnectorsPage onKeychain={() => setSettings("keychains")} /></Lazily>
        ) : route === INBOX_ROUTE ? (
          // ⭐⭐ W32-T04 (R7, C3, wirings 1+5) — THE INBOX MODULE. Same division as Connectors:
          // the module owns the QUESTION, the frame owns the DOOR.
          //
          // ⛔ `onOpenTarget` IS REQUIRED ON THE CALLEE, and that is a lesson written as a type.
          // An optional callback the frame forgot to pass degrades to "clicking an Inbox item
          // does nothing" — indistinguishable from "the feature was never built", and red in no
          // gate. Required means `tsc` fails the moment this is unmounted.
          <Lazily surface="Inbox">
            <InboxPage
              onInbox={setInbox}
              onToast={setToast}
              /* The frame has ALREADY fetched this — it is what painted the badge the user just
                 clicked — so the module opens knowing the count instead of asserting "Nothing
                 new." while its own read is in flight (W31-T23, measured 3,280 ms live). */
              seed={inbox}
              onOpenTarget={(t) => {
                // ⭐ C3's dispatch is DATA, not a branch: `inboxModel.routeForTarget` owns the
                // target→surface question, so this is a switch over two literals it can exhaust
                // rather than a second copy of the topic→route table.
                const dest = routeForTarget(t);
                if (!dest) {
                  // ⛔ AN UNKNOWN MODULE MUST SAY SO, NEVER SILENTLY DO NOTHING. It means this
                  // tab is older than the server that sent the notification; a reader who clicks
                  // and sees no change concludes the Inbox is broken rather than that they should
                  // reload. `inboxModel.routeForTarget`'s own docstring requires this half.
                  setToast("This notification points at something this version cannot open yet — reload to update.");
                  return;
                }
                // ⚠ THE ORDER IS LOAD-BEARING, and it is the old pane's rule kept verbatim: the
                // hash is set FIRST so the surface is mounting (or already mounted) when the
                // event arrives. Dispatching first fires into a route that does not exist yet.
                // `signal` is `apiContract`'s helper — the same channel those surfaces' own
                // listeners use — rather than a second hand-rolled `dispatchEvent` here.
                if (dest.surface === "automation") {
                  window.location.hash = "#/automation";
                  signal(AUTOMATION_OPEN_EVENT, { autoId: dest.autoId, tab: dest.tab });
                  return;
                }
                window.location.hash = `#/${dest.key}`;
                // ⛔⛔ W32 (ASK C-17) — A SINGLE EMIT HERE IS SILENTLY DISCARDED ON A COLD
                // CLICK, and that is item 19's own failure mode surviving item 19.
                // `CustomerGrid` guards its listener with `detail.topic !== scope` and
                // `!views.some(v => v.id === detail.viewId)` — both CORRECT (an alert outlives
                // its view; one grid must not react to another's event) — so an emit fired the
                // instant the hash changes lands on a grid that has not fetched its views yet,
                // is dropped, and there is NO ACK. The table opens, the view is not selected,
                // and the click "worked".
                // ⚠ The ladder is C's, already built and gated in their module (5 attempts over
                // 0–2,600 ms; a truthy `emit` ends it early, which VIEW_OPEN never returns, so
                // it simply runs out). Cancel any ladder still running from a previous click.
                if (dest.viewId) {
                  viewEmitCancel.current?.();
                  viewEmitCancel.current = retryEmit(() => {
                    signal(VIEW_OPEN_EVENT, { topic: dest.key, viewId: dest.viewId });
                  });
                }
              }}
            />
          </Lazily>
        ) : route === QUERY_ROUTE ? (
          // ⭐⭐ W32-T05 (R1, C5, wirings 2 and 6) — THE QUERY MODULE, where AI-built views live.
          //
          // ⛔ `granted` IS REQUIRED, AND IT IS ALSO WHAT MAKES THIS A LEGAL CHROME ROUTE. It is
          // the nav entries this shell ALREADY holds from `/nav` — the set the SERVER decided this
          // session may see — so the page makes no listing call of its own and *"a chrome route
          // renders nothing the server did not already grant"* is true by construction. The AI
          // therefore cannot name a database the caller was not already given: C5's permission
          // clause is the existing wall re-used, never a second one built beside it.
          <Lazily surface="Query"><QueryPage granted={entries} /></Lazily>
        ) : route === ASSISTANT_ROUTE ? (
          // ⭐⭐ 2026-08-14 (owner item 2) — THE AI ASSISTANT, where the question is asked.
          //
          // ⛔ `granted` IS REQUIRED HERE FOR THE SAME REASON IT IS ON `QueryPage` ABOVE, and it
          // is now the more load-bearing of the two: this is the surface that NAMES a database to
          // the model. It is the nav's own entries — the set the server decided this session may
          // see — so *"a chrome route renders nothing the server did not already grant"* stays
          // true by construction, and the build door re-checks with the same wall regardless.
          <Lazily surface="Assistant"><AssistantPage granted={entries} /></Lazily>
        ) : nav.phase === "ready" ? (
          // ⭐ WAVE 23 item 9 (R7, C10) — HOME, AND IT IS THE FALLBACK RATHER THAN A ROUTE MATCH.
          //
          // ⛔ WHY `!active` AND NOT `route === HOME_ROUTE`. Three states have to land here and
          // only one of them is the literal hash: `#/home`, an EMPTY hash, and a route that no
          // longer resolves (a deleted table, a stale bookmark, a hand-typed key). `resolveRoute`
          // already funnels all three to "no entry" now that `defaultRoute` returns a chrome
          // route, so testing the literal would have left the other two on the "Nothing to show"
          // branch — a shell that looks broken as the reward for deleting a database, which is
          // the exact failure `removeDatabase`'s own note warns about from the other side.
          //
          // ⚠ AND THIS BRANCH ABSORBED WAVE 18's TENANT HERO (R4), which used to live below.
          // That hero said "Welcome — this workspace has no databases yet" plus one create
          // button, on precisely the state Home now owns: a ready nav with zero entries. Leaving
          // both reachable would put two welcome messages on one screen, which is the defect the
          // rail's own note at the empty-nav line already documents. Home's four cards ARE the
          // hero's create door, and its empty line carries the hero's sentence (HomePage's
          // `home-empty`, which branches on `entries.length === 0` for exactly this reason).
          // Booked as a dated amendment in the wave doc, since it moves an R4 surface.
          <Lazily surface="Home">
            <HomePage
              // ⭐ `dbEntries`, NOT `entries` — found by LOOKING at it (wave 24 close-out visual
              // pass), which is the only way it could have been found. The Automation SURFACE is a
              // granted nav entry with an href, so `allDatabases` drew it a tile under the heading
              // "Databases" — beside an "Automations" section listing the things it contains. The
              // rail has excluded it since wave 19 R10 for exactly this reason (`dbEntries`, :1261);
              // Home was drawing the unfiltered list.
              // ⚠ STILL THE GRANTED NAV, so the C10 law is untouched: `dbEntries` is `entries` minus
              // one key, not a list this frame invented.
              entries={dbEntries}
              recents={recents}
              automations={autoTiles}
              // ⭐ WAVE 24 item 14 — the templates CARD is boarded. It opens the same
              // under-construction note the AI assistant uses, rather than the picker.
              // ⚠ The flyout's "From a template" row is UNAFFECTED (R9 keeps it working) — see
              // HomePage's own note on why that asymmetry is deliberate rather than a miss.
              onTemplates={() => setAssistOpen("templates")}
              onNewDatabase={() => openNewDb("blank")}
              /* ⛔ `onAutomated` LEFT WITH THE CARD IT OPENED (wave 25 item 5a, R8). */
              onConnectors={() => {
                window.location.hash = `#/${CONNECTORS_ROUTE}`;
              }}
              // The same two-part move every click-through in this frame makes: the frame owns the
              // hash, the surface owns which automation is selected. Route, then ASK.
              onOpenAutomation={(autoId) => {
                window.location.hash = "#/automation";
                signal(AUTOMATION_OPEN_EVENT, { autoId });
              }}
            />
          </Lazily>
        ) : nav.phase === "error" ? (
          // ⚠ WAVE 17 ITEM 4 (R6) — THE ERROR AND THE EMPTY ARE DIFFERENT SENTENCES, and this
          // branch is what keeps them apart. `active` resolves from `entries`, which is empty
          // while the nav is IN FLIGHT, so every first login used to land on a pane stating the
          // single worst thing this frame could say to a new user for as long as a round trip
          // took. WAVE 23 keeps that separation and simplifies its shape: `ready` now goes to
          // Home above (which welcomes an empty workspace properly), so this is only ever the
          // nav that FAILED, and the nested ternary that used to sort the two is gone.
          <div className="shell-placeholder">
            <h1>Nothing to show</h1>
            <p>The navigation service did not answer. Reload to retry.</p>
          </div>
        ) : (
          // Still asking (`loading`, or the `idle` beat before the effect runs).
          <div className="shell-loading">
            <span className="lp-spin lp-spin--lg" role="status" aria-label="Loading" />
          </div>
        )}
        </ErrorBoundary>
      </main>

      {/* The server's own confirmation of a write (X2's `toast`). In standalone
          it is the ONLY feedback for the events whose effect the payload does
          not yet echo back — cohort membership, list adds, folder moves. */}
      {/* Wave 18 (owner item 3): the boarded door.
          ⭐ 2026-08-14 — IT IS THE TEMPLATES DOOR ONLY NOW. The assistant arm is gone with the
          boarding: that surface exists (`#/assistant`), so an "under construction" note for it
          would be a lie about a working feature. Templates is a SEPARATE boarded door (wave 24
          item 14) and is deliberately left exactly as it was — the owner unblocked the assistant,
          not the template picker. */}
      {assistOpen ? (
        <div className="shell-newdb-scrim" onClick={() => setAssistOpen(false)}>
          <div
            className="shell-newdb shell-assist-note"
            role="dialog"
            aria-label="Templates"
            onClick={(e) => e.stopPropagation()}
          >
            <h2>Templates</h2>
            <p className="shell-newdb-sub">
              Under construction. Curated template sets are being built and will open here in
              a later release.
            </p>
            <div className="shell-newdb-actions">
              <button type="button" className="login-submit" onClick={() => setAssistOpen(false)}>
                Close
              </button>
            </div>
          </div>
        </div>
      ) : null}

      {/* Wave 18 (C3-UT): the New-database dialog. Scrim click cancels unless mid-create. */}
      {newDb ? (
        <div
          className="shell-newdb-scrim"
          onClick={() => {
            if (!newDb.busy) setNewDb(null);
          }}
        >
          <div
            className="shell-newdb"
            role="dialog"
            aria-label="New database"
            onClick={(e) => e.stopPropagation()}
          >
            <h2>New database</h2>
            {/* ⭐ WAVE 23 C10 — THE CHOICE. One-line rows, not paragraphs: the explanation lives
                where the DECISION is made and stops there (R13). The dialog's old sub-line ("a
                blank database… nothing here connects to a source") said one of these things as if
                it were the only one, so it moved onto the row it actually describes.
                ⭐ WAVE 25 item 5a (R8) — IT WAS A THREE-WAY CHOICE AND THE THIRD ROW IS DELETED.
                Two rows now, and they are both genuinely modes of this dialog, which the third
                never was: "Automated" wore no `role="radio"` because it LEFT (see its own deleted
                note) — a row inside a `radiogroup` that could not be checked. R8 removes the
                option; the anomaly in its markup was the shape of the problem all along. */}
            <div className="shell-newdb-kinds" role="radiogroup" aria-label="What to create">
              <button
                type="button"
                role="radio"
                aria-checked={newDb.mode === "blank"}
                className={"shell-newdb-kind" + (newDb.mode === "blank" ? " is-on" : "")}
                disabled={newDb.busy}
                onClick={() => setNewDb({ ...newDb, mode: "blank", err: "" })}
              >
                <span className="shell-newdb-kind-name">Blank</span>
                <span className="shell-newdb-kind-detail">
                  An empty database — add fields and records once it opens.
                </span>
              </button>
              <button
                type="button"
                role="radio"
                aria-checked={newDb.mode === "template"}
                className={"shell-newdb-kind" + (newDb.mode === "template" ? " is-on" : "")}
                disabled={newDb.busy}
                onClick={() => setNewDb({ ...newDb, mode: "template", err: "" })}
              >
                <span className="shell-newdb-kind-name">From a template</span>
                <span className="shell-newdb-kind-detail">
                  Add a curated set of views to a database you already have.
                </span>
              </button>
            </div>
            {newDb.mode === "template" ? (
              // WAVE 23 C12 (wiring W23-W6) — the picker. It applies views to an EXISTING
              // database rather than making one, which is what a platform-curated template is:
              // a set of saved views, not a table (R10).
              <Lazily surface="Templates">
                <TemplatePicker
                  entries={dbEntries}
                  onToast={setToast}
                  onDone={(tableKey) => {
                    setNewDb(null);
                    window.location.hash = `#/${tableKey}`;
                  }}
                />
              </Lazily>
            ) : (
              <>
                <input
                  autoFocus
                  className="shell-newdb-input"
                  placeholder="Database name"
                  value={newDb.name}
                  maxLength={60}
                  disabled={newDb.busy}
                  onChange={(e) => setNewDb({ ...newDb, name: e.target.value })}
                  onKeyDown={(e) => {
                    if (e.key === "Enter") void createDb();
                    if (e.key === "Escape" && !newDb.busy) setNewDb(null);
                  }}
                />
                {newDb.err ? <p className="shell-newdb-err">{newDb.err}</p> : null}
                <div className="shell-newdb-actions">
                  <button
                    type="button"
                    onClick={() => setNewDb(null)}
                    disabled={newDb.busy}
                  >
                    Cancel
                  </button>
                  <button
                    type="button"
                    className="login-submit"
                    onClick={() => void createDb()}
                    disabled={newDb.busy || !newDb.name.trim()}
                  >
                    {newDb.busy ? "Creating…" : "Create database"}
                  </button>
                </div>
              </>
            )}
          </div>
        </div>
      ) : null}

      {settings ? (
        <Lazily surface="Settings">
          <SettingsModal
            user={session.user}
            section={settings}
            onSection={setSettings}
            onClose={() => setSettings(null)}
            onUser={(u) => setSession({ phase: "authed", user: u })}
            // Wave 15 — the nav already holds a server-filtered {key: label} for
            // every surface this account may open, so "Your access" names its
            // restrictions in the words the rail uses rather than in registry
            // keys. Derived here rather than mapped in the modal so there is only
            // one place either door learns what a module is called.
            moduleLabels={Object.fromEntries(entries.map((e) => [e.key, e.label]))}
          />
        </Lazily>
      ) : null}

      {/* ⭐⭐ W32-T04 / R7 — THE ALERTS POP-UP PANE IS GONE, NOT HIDDEN. It was mounted here as
          a sibling of <main>; its surface is now the `#/inbox` route above. C's `W32-T21` deletes
          `AlertsPane.tsx` itself and retargets `verify_alerts.py` onto the module — this frame no
          longer imports it, which is the half that makes the file dead rather than merely unused
          ([[artifact-with-no-importer]]). */}

      {/* C-SHARE (items 18/23/26): the access editor — one dialog, three kinds. */}
      {shareFor ? (
        <ShareDialog
          kind={shareFor.kind}
          id={shareFor.id}
          label={shareFor.label}
          /* ⭐ W33-T27 — the DATABASE a shared VIEW belongs to, which the publish control needs
             and the share request never carried. The emitter's value wins when it sends one
             (`CustomerGrid` is another lane's file this wave); otherwise the OPEN SURFACE's key,
             which is the same table by construction — a view's share dialog can only be opened
             from inside that view. ⚠ A non-view share passes nothing and the panel does not
             render, which is the same absence a non-publishable view produces. */
          topic={shareFor.topic || (active ? active.key : "")}
          me={session.user.username}
          onClose={() => setShareFor(null)}
          onToast={setToast}
        />
      ) : null}

      {/* C-SCHEMA: the database schema drawer, over everything but the toast. */}
      {schemaFor ? (
        <SchemaDrawer schemaKey={schemaFor} onClose={() => setSchemaFor(null)} />
      ) : null}

      {toast ? (
        <div className="shell-toast" role="status" aria-live="polite">
          {toast}
        </div>
      ) : null}
    </div>
  );
}