Widget Phase 2: events app consumes container_nav widgets

Day view and entry detail now load and render registered container_nav
widgets (e.g. market links) from the same container page — matching how
blog post pages work. Calendar-domain widgets are skipped since we're
already on a calendar page. Adds /w/<widget_domain>/ paginate route for
infinite scroll support.

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

bp/calendar_entry/routes.py

@@ -27,6 +27,8 @@ from datetime import datetime, timezone
 import math
 import logging
 
+from shared.services.widget_registry import widgets
+
 from ..ticket_types.routes import register as register_ticket_types
 
 from .admin.routes import register as register_admin
@@ -220,6 +222,26 @@ def register():
                             ticket_type_id=tt.id,
                         )
 
+        # Widget-driven container nav (market links, etc.)
+        container_nav_loaded = []
+        post_data = getattr(g, "post_data", None)
+        if post_data:
+            post_id = post_data["post"]["id"]
+            post_slug = post_data["post"]["slug"]
+            for w in widgets.container_nav:
+                if w.domain.startswith("calendar"):
+                    continue  # skip — we're already on a calendar page
+                try:
+                    wctx = await w.context_fn(
+                        g.s, container_type="page", container_id=post_id,
+                        post_slug=post_slug,
+                    )
+                    has_data = any(v for v in wctx.values() if isinstance(v, list) and v)
+                    if has_data:
+                        container_nav_loaded.append({"widget": w, "ctx": wctx})
+                except Exception:
+                    pass
+
         return {
             "entry": calendar_entry,
             "entry_posts": entry_posts,
@@ -227,7 +249,8 @@ def register():
             "ticket_sold_count": ticket_sold_count,
             "user_ticket_count": user_ticket_count,
             "user_ticket_counts_by_type": user_ticket_counts_by_type,
-        }        
+            "container_nav_widgets": container_nav_loaded,
+        }
     @bp.get("/")
     @require_admin
     async def get(entry_id: int, **rest):