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>

bp/__init__.py

@@ -1,3 +1,4 @@
 from .calendars.routes import register as register_calendars
 from .markets.routes import register as register_markets
 from .payments.routes import register as register_payments
+from .page.routes import register as register_page

bp/page/routes.py

@@ -0,0 +1,81 @@
+"""
+Page summary blueprint — shows upcoming events across all calendars
+for a container (e.g. the village hall).
+
+Routes:
+  GET /<slug>/          — full page with first page of entries
+  GET /<slug>/entries   — HTMX fragment for infinite scroll
+"""
+from __future__ import annotations
+
+from quart import Blueprint, g, request, render_template, make_response
+
+from shared.browser.app.utils.htmx import is_htmx_request
+from shared.infrastructure.cart_identity import current_cart_identity
+from shared.services.registry import services
+
+
+def register() -> Blueprint:
+    bp = Blueprint("page_summary", __name__)
+
+    async def _load_entries(post_id, page, per_page=20):
+        """Load upcoming entries + pending ticket counts for current user."""
+        entries, has_more = await services.calendar.upcoming_entries_for_container(
+            g.s, "page", post_id, page=page, per_page=per_page,
+        )
+
+        # Pending ticket counts keyed by entry_id
+        ident = current_cart_identity()
+        pending_tickets = {}
+        if entries:
+            tickets = await services.calendar.pending_tickets(
+                g.s, user_id=ident["user_id"], session_id=ident["session_id"],
+            )
+            for t in tickets:
+                if t.entry_id is not None:
+                    pending_tickets[t.entry_id] = pending_tickets.get(t.entry_id, 0) + 1
+
+        return entries, has_more, pending_tickets
+
+    @bp.get("/")
+    async def index():
+        post = g.post_data["post"]
+        view = request.args.get("view", "list")
+        page = int(request.args.get("page", 1))
+
+        entries, has_more, pending_tickets = await _load_entries(post["id"], page)
+
+        ctx = dict(
+            entries=entries,
+            has_more=has_more,
+            pending_tickets=pending_tickets,
+            page=page,
+            view=view,
+        )
+
+        if is_htmx_request():
+            html = await render_template("_types/page_summary/_main_panel.html", **ctx)
+        else:
+            html = await render_template("_types/page_summary/index.html", **ctx)
+
+        return await make_response(html, 200)
+
+    @bp.get("/entries")
+    async def entries_fragment():
+        post = g.post_data["post"]
+        view = request.args.get("view", "list")
+        page = int(request.args.get("page", 1))
+
+        entries, has_more, pending_tickets = await _load_entries(post["id"], page)
+
+        html = await render_template(
+            "_types/page_summary/_cards.html",
+            entries=entries,
+            has_more=has_more,
+            pending_tickets=pending_tickets,
+            page=page,
+            view=view,
+        )
+        return await make_response(html, 200)
+
+    return bp