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/models/note.py

@@ -61,11 +61,9 @@ class Note(Base, TimestampMixin, SoftDeleteMixin):
     recurrence_next_spawn_at: Mapped[datetime | None] = mapped_column(
         DateTime(timezone=True), nullable=True
     )
-    # Entity type — 'note' (default), 'person', 'place', 'list'
+    # Note type — 'note' (default) or 'process' (a stored process). Task-ness is
+    # tracked by `status`, not here. (person/place/list entity types removed 2026-07.)
     note_type: Mapped[str] = mapped_column(Text, default="note", server_default="note")
-    # Structured metadata for entity types (person/place/list)
-    # Named 'entity_meta' to avoid collision with SQLAlchemy's reserved 'metadata' attribute
-    entity_meta: Mapped[dict | None] = mapped_column("metadata", JSONB, nullable=True)
     # Task sub-kind — 'work' (default), 'plan', or 'issue' (corrective work).
     # Only meaningful when the note is a task (status is not None); ordinary
     # notes keep the 'work' default and ignore it. Orthogonal to note_type
@@ -87,11 +85,6 @@ class Note(Base, TimestampMixin, SoftDeleteMixin):
     def is_task(self) -> bool:
         return self.status is not None
 
-    @property
-    def entity_type(self) -> str:
-        """Normalised type: 'note', 'person', 'place', or 'list'."""
-        return self.note_type or "note"
-
     def to_dict(self) -> dict:
         return {
             "id": self.id,
@@ -118,9 +111,8 @@ class Note(Base, TimestampMixin, SoftDeleteMixin):
                 else None
             ),
             "is_task": self.is_task,
-            "note_type": self.entity_type,
+            "note_type": self.note_type or "note",
             "task_kind": self.task_kind,
-            "metadata": self.entity_meta or {},
             "created_at": self.created_at.isoformat(),
             "updated_at": self.updated_at.isoformat(),
         }