feat(notes): accept and return description field through service and routes

create_note service accepts a new description kwarg and forwards it to the
Note constructor. PUT/PATCH/POST routes include description in the field
whitelist. update_note already passed **fields through setattr, so the new
column is reachable without touching that signature.

src/fabledassistant/routes/notes.py

@@ -112,6 +112,7 @@ async def create_note_route():
             uid,
             title=data.get("title", ""),
             body=body,
+            description=data.get("description"),
             tags=tags,
             parent_id=data.get("parent_id"),
             project_id=project_id,
@@ -215,7 +216,7 @@ async def update_note_route(note_id: int):
     uid = get_current_user_id()
     data = await request.get_json()
     fields = {}
-    for key in ("title", "body", "parent_id", "project_id", "milestone_id", "status", "priority", "note_type"):
+    for key in ("title", "body", "description", "parent_id", "project_id", "milestone_id", "status", "priority", "note_type"):
         if key in data:
             fields[key] = data[key]
     if "metadata" in data:
@@ -250,7 +251,7 @@ async def patch_note_route(note_id: int):
     uid = get_current_user_id()
     data = await request.get_json()
     fields = {}
-    for key in ("title", "body", "parent_id", "project_id", "milestone_id", "status", "priority", "note_type"):
+    for key in ("title", "body", "description", "parent_id", "project_id", "milestone_id", "status", "priority", "note_type"):
         if key in data:
             fields[key] = data[key]
     if "metadata" in data: