refactor(scribe): retire calendar/events + person/place/list entities (backend)

Narrow Scribe to a Claude-Code work system-of-record (milestone #194,
decision note #1759). Wholesale removal per rule #22 — backend + schema half.

Calendar/events + CalDAV: delete models/event, services/{events,caldav,
caldav_sync}, routes/events, mcp/tools/events; strip event branches from
backup (bump v3->v4), dashboard (upcoming_events), trash, recent, and the
mcp server read-only allowlist + instructions.

Typed entities (person/place/list): delete mcp/tools/entities; drop the
notes.metadata (entity_meta) column from model/service/routes and the
knowledge browse service. note_type STAYS — it also marks 'process' notes.

Scheduler: event_scheduler -> recurrence_scheduler, keeping only the
recurring-task spawn job (drops event reminders + CalDAV sync).

Schema: migration 0069 drops the events table + notes.metadata column +
orphan caldav settings rows (faithful downgrade recreates them).

KEEP: recurrence.py (task recurrence), notifications task reminders, graph
view, and every work surface. Frontend + plugin/docs true-up follow next.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BPtbSzA4JLMAKgFZ8VTg7Q

src/scribe/app.py

@@ -21,7 +21,6 @@ from scribe.routes.shares import shares_bp
 from scribe.routes.in_app_notifications import notifications_bp
 from scribe.routes.users import users_bp
 from scribe.routes.api_keys import api_keys_bp
-from scribe.routes.events import events_bp
 from scribe.routes.search import search_bp
 from scribe.routes.profile import profile_bp
 from scribe.routes.knowledge import knowledge_bp
@@ -84,7 +83,6 @@ def create_app() -> Quart:
     app.register_blueprint(notifications_bp)
     app.register_blueprint(users_bp)
     app.register_blueprint(api_keys_bp)
-    app.register_blueprint(events_bp)
     app.register_blueprint(search_bp)
     app.register_blueprint(profile_bp)
     app.register_blueprint(knowledge_bp)
@@ -173,9 +171,9 @@ def create_app() -> Quart:
 
         asyncio.create_task(_delayed_backfill())
 
-        # Event scheduler (reminders + CalDAV pull sync)
-        from scribe.services.event_scheduler import start_event_scheduler
-        start_event_scheduler(asyncio.get_running_loop())
+        # Recurrence scheduler (recurring-task spawn every 15m)
+        from scribe.services.recurrence_scheduler import start_recurrence_scheduler
+        start_recurrence_scheduler(asyncio.get_running_loop())
 
         # Version-pinning scheduler (daily auto-pin scan at 03:00 UTC)
         from scribe.services.version_pinning_scheduler import (
@@ -204,8 +202,8 @@ def create_app() -> Quart:
 
     @app.after_serving
     async def shutdown():
-        from scribe.services.event_scheduler import stop_event_scheduler
-        stop_event_scheduler()
+        from scribe.services.recurrence_scheduler import stop_recurrence_scheduler
+        stop_recurrence_scheduler()
         from scribe.services.version_pinning_scheduler import (
             stop_version_pinning_scheduler,
         )