Add DB write-lock setting with HF-friendly runtime controls

app.py

@@ -111,6 +111,8 @@ from db_store import (
     set_context_payload,
     update_item_verified,
     upsert_inventory_item,
+    set_db_write_lock,
+    get_db_write_lock,
 )
 
 logger = logging.getLogger("uvicorn.error")
@@ -327,6 +329,8 @@ PREVIOUS_DATA_ROOT_DB = DATA_ROOT / "app.db"
 SEED_DB_LOCAL = APP_HOME / "seed" / "app.db"
 # Remote seeding disabled by default to avoid unintended downloads; set SEED_DB_URL to enable.
 SEED_DB_URL = os.environ.get("SEED_DB_URL") or None
+_DB_WRITE_LOCK_ENV = (os.environ.get("DB_WRITE_LOCK") or "").strip().lower()
+DB_WRITE_LOCK_FORCED = _DB_WRITE_LOCK_ENV in {"1", "true", "yes", "on"} if _DB_WRITE_LOCK_ENV else None
 
 
 def _is_valid_sqlite(path: Path) -> bool:
@@ -418,6 +422,30 @@ def _bootstrap_db(force: bool = False):
 _bootstrap_db()
 configure_db(DB_PATH)
 
+
+def _apply_db_write_lock_setting(candidate=None):
+    """
+    Apply DB write-lock policy.
+
+    Priority:
+    1) Environment override DB_WRITE_LOCK (if set)
+    2) Persisted settings_meta.db_write_lock
+    """
+    if DB_WRITE_LOCK_FORCED is not None:
+        set_db_write_lock(DB_WRITE_LOCK_FORCED)
+        return DB_WRITE_LOCK_FORCED
+    if candidate is None:
+        try:
+            meta = get_settings_meta() or {}
+            candidate = bool(meta.get("db_write_lock"))
+        except Exception:
+            candidate = False
+    set_db_write_lock(bool(candidate))
+    return bool(candidate)
+
+
+_apply_db_write_lock_setting()
+
 DEFAULT_store_LABEL = "Default"
 DEFAULT_store = None
 
@@ -1121,6 +1149,8 @@ def get_defaults():
         "rep_penalty": 1.1,
         "mission_context": "Isolated Medical Station offshore.",
         "user_mode": "user",
+        "db_write_lock": bool(get_db_write_lock()),
+        "db_write_lock_forced": DB_WRITE_LOCK_FORCED is not None,
         "last_prompt_verbatim": "",
         "vaccine_types": [
             "Diphtheria, Tetanus, and Pertussis (DTaP/Tdap)",
@@ -1260,7 +1290,9 @@ def db_op(cat, data=None, store=None):
             set_settings_meta(
                 user_mode=data.get("user_mode"),
                 offline_force_flags=data.get("offline_force_flags"),
+                db_write_lock=data.get("db_write_lock"),
             )
+            _apply_db_write_lock_setting(data.get("db_write_lock"))
             return {**get_defaults(), **data}
         if cat == "inventory":
             if not isinstance(data, list):
@@ -2526,6 +2558,8 @@ async def db_status():
             "stores": 1,
             "crew_rows": crew,
             "vessel_rows": vessel,
+            "db_write_lock": bool(get_db_write_lock()),
+            "db_write_lock_forced": DB_WRITE_LOCK_FORCED is not None,
         }
     except Exception as e:
         return JSONResponse({"error": str(e)}, status_code=status.HTTP_500_INTERNAL_SERVER_ERROR)
@@ -2550,6 +2584,7 @@ async def db_create():
         if DB_PATH.exists():
             DB_PATH.unlink()
         configure_db(DB_PATH)
+        _apply_db_write_lock_setting()
         _store_dirs(DEFAULT_store_LABEL)
         return {"status": "created"}
     except Exception as e:
@@ -2580,6 +2615,7 @@ async def db_upload(file: UploadFile = File(...)):
             tmp.close()
         shutil.move(tmp.name, DB_PATH)
         configure_db(DB_PATH)
+        _apply_db_write_lock_setting()
         _store_dirs(DEFAULT_store_LABEL)
         return {"status": "uploaded"}
     except Exception as e:

db_store.py

@@ -26,6 +26,7 @@ from typing import Optional, Any, Dict
 logger = logging.getLogger("uvicorn.error")
 
 DB_PATH: Path
+DB_WRITE_LOCK = False
 TRIAGE_TREE_DEFAULT_JSON_PATH = Path(__file__).resolve().parent / "seed" / "triage_prompt_tree.default.json"
 
 
@@ -39,6 +40,17 @@ def configure_db(path: Path):
     _upgrade_schema()
 
 
+def set_db_write_lock(enabled: bool):
+    """Set database query-only mode for all future connections."""
+    global DB_WRITE_LOCK
+    DB_WRITE_LOCK = bool(enabled)
+
+
+def get_db_write_lock() -> bool:
+    """Return whether DB write lock (query-only mode) is enabled."""
+    return bool(DB_WRITE_LOCK)
+
+
 def _conn():
     """
      Conn helper.
@@ -50,6 +62,10 @@ def _conn():
         conn.execute("PRAGMA foreign_keys = ON;")
         # Keep temp tables in memory to avoid filesystem issues when sorting large BLOB rows
         conn.execute("PRAGMA temp_store = MEMORY;")
+        if DB_WRITE_LOCK:
+            conn.execute("PRAGMA query_only = ON;")
+        else:
+            conn.execute("PRAGMA query_only = OFF;")
     except Exception:
         pass
     return conn
@@ -242,6 +258,7 @@ def _init_db():
                 id INTEGER PRIMARY KEY CHECK (id = 1),
                 user_mode TEXT,
                 offline_force_flags INTEGER DEFAULT 0,
+                db_write_lock INTEGER DEFAULT 0,
                 last_prompt_verbatim TEXT,
                 updated_at TEXT NOT NULL
             );
@@ -857,21 +874,24 @@ def _maybe_migrate_settings_meta(conn, now):
         data = {}
     user_mode = data.get("user_mode")
     offline_force_flags = 1 if data.get("offline_force_flags") else 0
+    db_write_lock = 1 if data.get("db_write_lock") else 0
     last_prompt_verbatim = data.get("last_prompt_verbatim")
     _ensure_settings_meta_columns(conn)
     conn.execute(
         """
-        INSERT INTO settings_meta(id, user_mode, offline_force_flags, last_prompt_verbatim, updated_at)
-        VALUES(1, :user_mode, :offline_force_flags, :last_prompt_verbatim, :updated_at)
+        INSERT INTO settings_meta(id, user_mode, offline_force_flags, db_write_lock, last_prompt_verbatim, updated_at)
+        VALUES(1, :user_mode, :offline_force_flags, :db_write_lock, :last_prompt_verbatim, :updated_at)
         ON CONFLICT(id) DO UPDATE SET
             user_mode=excluded.user_mode,
             offline_force_flags=excluded.offline_force_flags,
+            db_write_lock=excluded.db_write_lock,
             last_prompt_verbatim=excluded.last_prompt_verbatim,
             updated_at=excluded.updated_at;
         """,
         {
             "user_mode": user_mode,
             "offline_force_flags": offline_force_flags,
+            "db_write_lock": db_write_lock,
             "last_prompt_verbatim": last_prompt_verbatim,
             "updated_at": now,
         },
@@ -2215,6 +2235,8 @@ def _ensure_settings_meta_columns(conn):
         names = {c["name"] for c in cols}
         if "last_prompt_verbatim" not in names:
             conn.execute("ALTER TABLE settings_meta ADD COLUMN last_prompt_verbatim TEXT;")
+        if "db_write_lock" not in names:
+            conn.execute("ALTER TABLE settings_meta ADD COLUMN db_write_lock INTEGER DEFAULT 0;")
     except Exception as exc:
         logger.warning("Unable to add settings_meta columns: %s", exc)
 
@@ -3781,13 +3803,14 @@ def get_settings_meta():
     with _conn() as conn:
         _ensure_settings_meta_columns(conn)
         row = conn.execute(
-            "SELECT user_mode, offline_force_flags, last_prompt_verbatim FROM settings_meta WHERE id=1"
+            "SELECT user_mode, offline_force_flags, db_write_lock, last_prompt_verbatim FROM settings_meta WHERE id=1"
         ).fetchone()
     if not row:
         return {}
     return {
         "user_mode": row["user_mode"],
         "offline_force_flags": bool(row["offline_force_flags"]),
+        "db_write_lock": bool(row["db_write_lock"]),
         "last_prompt_verbatim": row["last_prompt_verbatim"],
     }
 
@@ -3795,6 +3818,7 @@ def get_settings_meta():
 def set_settings_meta(
     user_mode: str = None,
     offline_force_flags: bool = None,
+    db_write_lock: bool = None,
     last_prompt_verbatim: str = None,
 ):
     """
@@ -3805,17 +3829,18 @@ def set_settings_meta(
     with _conn() as conn:
         _ensure_settings_meta_columns(conn)
         existing = conn.execute(
-            "SELECT user_mode, offline_force_flags, last_prompt_verbatim FROM settings_meta WHERE id=1"
+            "SELECT user_mode, offline_force_flags, db_write_lock, last_prompt_verbatim FROM settings_meta WHERE id=1"
         ).fetchone()
         if existing is None:
             conn.execute(
                 """
-                INSERT INTO settings_meta(id, user_mode, offline_force_flags, last_prompt_verbatim, updated_at)
-                VALUES(1, :user_mode, :offline_force_flags, :last_prompt_verbatim, :updated_at)
+                INSERT INTO settings_meta(id, user_mode, offline_force_flags, db_write_lock, last_prompt_verbatim, updated_at)
+                VALUES(1, :user_mode, :offline_force_flags, :db_write_lock, :last_prompt_verbatim, :updated_at)
                 """,
                 {
                     "user_mode": user_mode,
                     "offline_force_flags": 1 if offline_force_flags else 0,
+                    "db_write_lock": 1 if db_write_lock else 0,
                     "last_prompt_verbatim": last_prompt_verbatim,
                     "updated_at": now,
                 },
@@ -3826,6 +3851,7 @@ def set_settings_meta(
                 UPDATE settings_meta
                 SET user_mode=COALESCE(:user_mode, user_mode),
                     offline_force_flags=COALESCE(:offline_force_flags, offline_force_flags),
+                    db_write_lock=COALESCE(:db_write_lock, db_write_lock),
                     last_prompt_verbatim=COALESCE(:last_prompt_verbatim, last_prompt_verbatim),
                     updated_at=:updated_at
                 WHERE id=1
@@ -3833,6 +3859,7 @@ def set_settings_meta(
                 {
                     "user_mode": user_mode,
                     "offline_force_flags": None if offline_force_flags is None else (1 if offline_force_flags else 0),
+                    "db_write_lock": None if db_write_lock is None else (1 if db_write_lock else 0),
                     "last_prompt_verbatim": last_prompt_verbatim,
                     "updated_at": now,
                 },

static/js/settings.js

@@ -113,7 +113,9 @@ const DEFAULT_SETTINGS = {
     pharmacy_labels: ["Antibiotic", "Analgesic", "Cardiac", "Respiratory", "Gastrointestinal", "Endocrine", "Emergency"],
     equipment_categories: [],
     consumable_categories: [],
-    offline_force_flags: false
+    offline_force_flags: false,
+    db_write_lock: false,
+    db_write_lock_forced: false,
 };
 
 // ============================================================================
@@ -349,6 +351,16 @@ function applySettingsToUI(data = {}) {
             }
         }
     });
+    const dbWriteLockEl = document.getElementById('db_write_lock');
+    const dbWriteLockForcedNote = document.getElementById('db-write-lock-forced-note');
+    if (dbWriteLockEl) {
+        const forced = !!merged.db_write_lock_forced;
+        dbWriteLockEl.disabled = forced;
+        dbWriteLockEl.title = forced ? 'Locked by environment variable DB_WRITE_LOCK' : '';
+        if (dbWriteLockForcedNote) {
+            dbWriteLockForcedNote.style.display = forced ? 'block' : 'none';
+        }
+    }
     setUserMode(merged.user_mode);
     try { localStorage.setItem('user_mode', merged.user_mode || 'user'); } catch (err) { /* ignore */ }
     window.CACHED_SETTINGS = merged;
@@ -1575,7 +1587,7 @@ async function saveSettings(showAlert = true, reason = 'manual') {
     try {
         const s = {};
         const numeric = new Set(['tr_temp','tr_tok','tr_p','tr_k','in_temp','in_tok','in_p','in_k','rep_penalty']);
-        ['triage_instruction','inquiry_instruction','tr_temp','tr_tok','tr_p','tr_k','in_temp','in_tok','in_p','in_k','mission_context','rep_penalty','user_mode'].forEach(k => {
+        ['triage_instruction','inquiry_instruction','tr_temp','tr_tok','tr_p','tr_k','in_temp','in_tok','in_p','in_k','mission_context','rep_penalty','user_mode','db_write_lock'].forEach(k => {
             const el = document.getElementById(k);
             if (!el) return;
             const val = el.type === 'checkbox' ? el.checked : el.value;

templates/index.html

@@ -1181,6 +1181,13 @@
                             <div style="margin-top:10px;">
                                 <a class="btn btn-sm" style="background:#b23b00; display:inline-block;" href="/logout?fresh=1" onclick="if (typeof forceClearCache === 'function') { forceClearCache(); return false; }"><span class="dev-tag">dev:cache-bust</span>Force Reload</a>
                             </div>
+                            <label style="display:flex; align-items:center; gap:8px; font-size:12px; color:#333; margin-top:10px;">
+                                <input type="checkbox" id="db_write_lock" />
+                                Database Write Lock (read-only mode)
+                            </label>
+                            <div id="db-write-lock-forced-note" style="margin-top:6px; font-size:12px; color:#b23b00; display:none;">
+                                Write lock is forced by environment variable <code>DB_WRITE_LOCK</code>.
+                            </div>
                             <div style="margin-top:8px; font-size:12px; color:#555;">
                                 User: hides advanced controls. Advanced: shows prompt tools. Developer: also shows dev tags.
                             </div>