Add /api/quick-capture endpoint for mobile/external clients

Single POST that classifies natural-language text and creates the
appropriate item (note, task, event, or todo) in one synchronous
request — no SSE, no conversation context needed.

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

src/fabledassistant/app.py

@@ -13,6 +13,7 @@ from fabledassistant.routes.api import api
 from fabledassistant.routes.auth import auth_bp
 from fabledassistant.routes.chat import chat_bp
 from fabledassistant.routes.notes import notes_bp
+from fabledassistant.routes.quick_capture import quick_capture_bp
 from fabledassistant.routes.settings import settings_bp
 from fabledassistant.routes.tasks import tasks_bp
 
@@ -44,6 +45,7 @@ def create_app() -> Quart:
     app.register_blueprint(auth_bp)
     app.register_blueprint(chat_bp)
     app.register_blueprint(notes_bp)
+    app.register_blueprint(quick_capture_bp)
     app.register_blueprint(settings_bp)
     app.register_blueprint(tasks_bp)