Add fragment blueprint + sync shared: micro-frontend infrastructure

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

app.py

@@ -8,7 +8,7 @@ from jinja2 import FileSystemLoader, ChoiceLoader
 
 from shared.infrastructure.factory import create_base_app
 
-from bp import register_all_events, register_calendars, register_markets, register_payments, register_page
+from bp import register_all_events, register_calendars, register_markets, register_payments, register_page, register_fragments
 
 
 async def events_context() -> dict:
@@ -85,6 +85,8 @@ def create_app() -> "Quart":
         url_prefix="/<slug>/payments",
     )
 
+    app.register_blueprint(register_fragments())
+
     # --- Auto-inject slug into url_for() calls ---
     @app.url_value_preprocessor
     def pull_slug(endpoint, values):