fix: rename Note.metadata → entity_meta (reserved by SQLAlchemy Declarative API)

SQLAlchemy reserves 'metadata' as a class attribute on declarative models.
Renamed to 'entity_meta' with explicit column name 'metadata' so the DB
column is unchanged but the Python attribute no longer conflicts.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/knowledge.py

@@ -12,7 +12,7 @@ _SNIPPET_LEN = 200
 
 
 def _note_to_item(note: Note) -> dict:
-    meta = note.metadata or {}
+    meta = note.entity_meta or {}
     item: dict = {
         "id": note.id,
         "note_type": note.entity_type,
@@ -184,14 +184,14 @@ async def get_people_and_places_context(user_id: int) -> str:
     if people:
         parts = []
         for p in people:
-            meta = p.metadata or {}
+            meta = p.entity_meta or {}
             rel = meta.get("relationship", "")
             parts.append(f"{p.title}" + (f" ({rel})" if rel else ""))
         lines.append("Known people: " + ", ".join(parts))
     if places:
         parts = []
         for p in places:
-            meta = p.metadata or {}
+            meta = p.entity_meta or {}
             addr = meta.get("address", "")
             parts.append(f"{p.title}" + (f" – {addr}" if addr else ""))
         lines.append("Known places: " + "; ".join(parts))