[NOTICKET] docs(dev-plan): mark #15 done (slow-path verified) + sync status

- #15: slow-path persistence verified locally (in-process) — structured_flow on
Titanic.csv -> AnalysisRecord persisted (substantive) -> POST /report 201.
- #5/#6/#17 marked done; critical-path + demo-gate updated so #16 is the only
remaining blocker before the Swagger run.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

DEV_PLAN.md

@@ -96,7 +96,7 @@ Status legend: ⬜ not started · 🔄 in progress · ✅ done · ⛔ blocked ·
 | 12 | Reconcile/open the `list_tools` PR cleanly (stacked commits) | Rifqi | ✅ | N/A — we develop directly on the single active branch `pr/4` (KM-652 + KM-678 already stacked there); no separate PR to reconcile |
 | 13 | Merge HF Python build → test 4 endpoints via Swagger | Sofhia + Harry | ⬜ | Not E2E. Blocked by #15 |
 | 14 | `analysis_records` home | Rifqi + Sofhia + lead | ⬜ → required | Records-based decided ⇒ no longer conditional; see #16 |
-| 15 | Flip `ENABLE_SLOW_PATH=true` on HF + verify an `AnalysisRecord` persists from a `structured_flow` question | Rifqi | ⬜ new | Precondition for any report demo (#13) |
+| 15 | Flip `ENABLE_SLOW_PATH=true` + verify an `AnalysisRecord` persists from a `structured_flow` question | Rifqi | ✅ | Verified locally 2026-06-25 (in-process). structured_flow on Titanic.csv → 3-task plan `check_data→retrieve_data→analyze_aggregate` (all success) → AnalysisRecord persisted (substantive) → `report_floor` pass → report generates (201). HF env-flip + Swagger run folds into #13 |
 | 16 | Decide `analysis_records` creation under `SKIP_INIT_DB`: dedorch migration (Harry) or Python carve-out | Rifqi + Harry | ⬜ new | Table won't exist post-cutover otherwise |
 | 17 | Reconcile report contract with records-based: remove/flag `chat_history` | Sofhia/Rifqi | ✅ | Nothing to remove — `chat_history` was never in the report contract/code (only in help.md). Confirmed via grep; API_ENDPOINTS.md §5 documents the clean contract |
 | 18 | Confirm Go owns ALL analysis-state writes + both creation gates; make Python `state_store.ensure` read-only | Rifqi + Harry | ⬜ new | Extends #7 to the full decision #4 (G5) |
@@ -105,11 +105,12 @@ Status legend: ⬜ not started · 🔄 in progress · ✅ done · ⛔ blocked ·
 
 ## 5. Critical path & sequencing
 
-- **Critical path:** #3 → #4 (de-risked by getattr tolerance). #15 + #16 → #13.
+- **Critical path:** #3 → #4 (de-risked by getattr tolerance). #16 → #13 (#15 ✅).
 - **Parallelizable now (no blockers):** #1+#2 (together), #8, #10, #11, #12.
 - **Harry-blocked:** #3 (blocks #4), #7 (Go endpoint), #16/#18 (dedorch + Go ownership).
-- **Demo gate for Wednesday (#13):** slow path on (#15) + records table exists (#16) + report contract
-  settled (#17). Without #15/#16 the report endpoint 409s in Swagger.
+- **Demo gate for Wednesday (#13):** slow path verified (#15 ✅, local) + report contract settled
+  (#17 ✅) + records table exists post-cutover (#16, the one open item). #16 is now the only blocker
+  before the Swagger run.
 
 ## 6. Decisions still open (need the team / Harry / lead)