Phase 4: add container-nav/cards fragment handlers, use market fragment

Events provides container-nav (calendar entries + links) and
container-cards (batch entries for blog listing) as fragments.
Day and entry routes fetch market container-nav via fragment instead
of widget registry.

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

bp/day/routes.py

@@ -11,7 +11,7 @@ from bp.calendar_entries.routes import register as register_calendar_entries
 from .admin.routes import register as register_admin
 
 from shared.browser.app.redis_cacher import cache_page
-from shared.services.widget_registry import widgets
+from shared.infrastructure.fragments import fetch_fragment
 
 from models.calendars import CalendarSlot  # add this import
 
@@ -78,25 +78,17 @@ def register():
         result = await g.s.execute(stmt)
         day_slots = list(result.scalars())
 
-        # Widget-driven container nav (market links, etc.)
-        container_nav_loaded = []
+        # Fetch container nav from market (skip calendar — we're on a calendar page)
+        container_nav_html = ""
         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
+            container_nav_html = await fetch_fragment("market", "container-nav", params={
+                "container_type": "page",
+                "container_id": str(post_id),
+                "post_slug": post_slug,
+            })
 
         return {
             "qsession": qsession,
@@ -108,7 +100,7 @@ def register():
             "user_entries": visible.user_entries,
             "confirmed_entries": visible.confirmed_entries,
             "day_slots": day_slots,
-            "container_nav_widgets": container_nav_loaded,
+            "container_nav_html": container_nav_html,
         }
 
 
@@ -142,23 +134,21 @@ def register():
 
     @bp.get("/w/<widget_domain>/")
     async def widget_paginate(widget_domain: str, **kwargs):
-        """Generic paginated widget endpoint for infinite scroll."""
+        """Proxies paginated widget requests to the appropriate fragment provider."""
         page = int(request.args.get("page", 1))
         post_data = getattr(g, "post_data", None)
         if not post_data:
             abort(404)
         post_id = post_data["post"]["id"]
         post_slug = post_data["post"]["slug"]
-        for w in widgets.container_nav:
-            if w.domain == widget_domain:
-                ctx = await w.context_fn(
-                    g.s, container_type="page", container_id=post_id,
-                    post_slug=post_slug, page=page,
-                )
-                html = await render_template(
-                    w.template, ctx=ctx, post=post_data["post"],
-                )
-                return await make_response(html)
+
+        if widget_domain == "market":
+            html = await fetch_fragment("market", "container-nav", params={
+                "container_type": "page",
+                "container_id": str(post_id),
+                "post_slug": post_slug,
+            })
+            return await make_response(html or "")
         abort(404)
 
     return bp