API: no_project filter + project_id on tasks route

- list_notes(): add no_project param → Note.project_id.is_(None) filter
- GET /api/notes: expose ?no_project=true
- GET /api/tasks: add ?project_id= and ?no_project=true pass-through

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

src/fabledassistant/routes/tasks.py

@@ -27,6 +27,9 @@ async def list_tasks_route():
     limit = min(request.args.get("limit", 50, type=int), 500)
     offset = request.args.get("offset", 0, type=int)
 
+    project_id = request.args.get("project_id", type=int)
+    no_project = request.args.get("no_project", "").lower() == "true"
+
     due_before = parse_iso_date(request.args.get("due_before"), "due_before")
     if isinstance(due_before, tuple):
         return due_before
@@ -43,6 +46,8 @@ async def list_tasks_route():
         priority=priority,
         due_before=due_before,
         due_after=due_after,
+        project_id=project_id,
+        no_project=no_project,
         sort=sort,
         order=order,
         limit=limit,