Add village hall page summary with infinite scroll

New /<slug>/ route shows upcoming confirmed events across all calendars
for a container. Features list/tile view toggle, date-grouped cards,
ticket +/- cart widgets, and infinite scroll pagination.

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_calendars, register_markets, register_payments
+from bp import register_calendars, register_markets, register_payments, register_page
 
 
 async def events_context() -> dict:
@@ -55,6 +55,12 @@ def create_app() -> "Quart":
         app.jinja_loader,
     ])
 
+    # Page summary: /<slug>/ — upcoming events across all calendars
+    app.register_blueprint(
+        register_page(),
+        url_prefix="/<slug>",
+    )
+
     # Calendars nested under post slug: /<slug>/calendars/...
     app.register_blueprint(
         register_calendars(),