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/services/trash.py

@@ -14,7 +14,6 @@ from sqlalchemy import or_, select, update
 
 from scribe.models import async_session
 from scribe.models.note import Note
-from scribe.models.event import Event
 from scribe.models.project import Project
 from scribe.models.milestone import Milestone
 from scribe.models.rulebook import Rulebook, RulebookTopic, Rule
@@ -23,7 +22,6 @@ from scribe.models.rulebook import Rulebook, RulebookTopic, Rule
 _MODEL_FOR = {
     "note": Note,
     "task": Note,
-    "event": Event,
     "project": Project,
     "milestone": Milestone,
     "rulebook": Rulebook,
@@ -59,7 +57,7 @@ def _owner_clause(model, user_id: int):
                 select(Project.id).where(Project.user_id == user_id)
             ),
         )
-    # Note, Event, Project, Milestone all carry user_id directly.
+    # Note, Project, Milestone all carry user_id directly.
     return model.user_id == user_id
 
 
@@ -121,8 +119,6 @@ async def _cascade(session, user_id: int, etype: str, eid: int, batch: str, now)
             frontier = [c for c in children if c not in ids]
             ids.extend(frontier)
         await _set(session, Note, [Note.user_id == user_id, Note.id.in_(ids)], batch, now)
-    elif etype == "event":
-        await _set(session, Event, [Event.user_id == user_id, Event.id == eid], batch, now)
     elif etype == "rulebook":
         topic_ids = (await session.execute(
             select(RulebookTopic.id)
@@ -149,35 +145,18 @@ async def delete(user_id: int, entity_type: str, entity_id: int) -> str | None:
     """
     batch = str(uuid.uuid4())
     now = datetime.now(timezone.utc)
-    caldav_event: tuple[str, str] | None = None
     async with async_session() as session:
         if not await _exists_alive(session, user_id, entity_type, entity_id):
             return None
-        # Capture CalDAV linkage before soft-deleting so we can propagate the
-        # deletion to the external server (the row stays present locally).
-        if entity_type == "event":
-            row = (await session.execute(
-                select(Event.caldav_uid, Event.title).where(
-                    Event.id == entity_id, Event.user_id == user_id
-                )
-            )).first()
-            if row and row[0]:
-                caldav_event = (row[0], row[1])
         await _cascade(session, user_id, entity_type, entity_id, batch, now)
         await session.commit()
-    # Without this the soft-delete only hides the event locally and the remote
-    # copy lingers forever (and re-appears on any client syncing that server).
-    if caldav_event:
-        import asyncio
-        from scribe.services.events import _push_delete
-        asyncio.create_task(_push_delete(caldav_event[0], caldav_event[1], user_id))
     return batch
 
 
 # All soft-deletable models, and their trash-listing type label.
-_ALL = [Note, Event, Project, Milestone, Rulebook, RulebookTopic, Rule]
+_ALL = [Note, Project, Milestone, Rulebook, RulebookTopic, Rule]
 _TYPE = {
-    Note: "note", Event: "event", Project: "project", Milestone: "milestone",
+    Note: "note", Project: "project", Milestone: "milestone",
     Rulebook: "rulebook", RulebookTopic: "topic", Rule: "rule",
 }