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/fragments/routes.py

@@ -6,9 +6,10 @@ by other coop apps via the fragment client.
 
 from __future__ import annotations
 
-from quart import Blueprint, Response, request
+from quart import Blueprint, Response, g, render_template, request
 
 from shared.infrastructure.fragments import FRAGMENT_HEADER
+from shared.services.registry import services
 
 
 def register():
@@ -29,6 +30,70 @@ def register():
         html = await handler()
         return Response(html, status=200, content_type="text/html")
 
+    # --- container-nav fragment: calendar entries + calendar links -----------
+
+    async def _container_nav_handler():
+        container_type = request.args.get("container_type", "page")
+        container_id = int(request.args.get("container_id", 0))
+        post_slug = request.args.get("post_slug", "")
+        paginate_url_base = request.args.get("paginate_url", "")
+        page = int(request.args.get("page", 1))
+        exclude = request.args.get("exclude", "")
+        excludes = [e.strip() for e in exclude.split(",") if e.strip()]
+
+        html_parts = []
+
+        # Calendar entries nav
+        if not any(e.startswith("calendar") for e in excludes):
+            entries, has_more = await services.calendar.associated_entries(
+                g.s, container_type, container_id, page,
+            )
+            if entries:
+                html_parts.append(await render_template(
+                    "fragments/container_nav_entries.html",
+                    entries=entries, has_more=has_more,
+                    page=page, post_slug=post_slug,
+                    paginate_url_base=paginate_url_base,
+                ))
+
+        # Calendar links nav
+        if not any(e.startswith("calendar") for e in excludes):
+            calendars = await services.calendar.calendars_for_container(
+                g.s, container_type, container_id,
+            )
+            if calendars:
+                html_parts.append(await render_template(
+                    "fragments/container_nav_calendars.html",
+                    calendars=calendars, post_slug=post_slug,
+                ))
+
+        return "\n".join(html_parts)
+
+    _handlers["container-nav"] = _container_nav_handler
+
+    # --- container-cards fragment: entries for blog listing cards ------------
+
+    async def _container_cards_handler():
+        post_ids_raw = request.args.get("post_ids", "")
+        post_slugs_raw = request.args.get("post_slugs", "")
+        post_ids = [int(x) for x in post_ids_raw.split(",") if x.strip()]
+        post_slugs = [x.strip() for x in post_slugs_raw.split(",") if x.strip()]
+        if not post_ids:
+            return ""
+
+        # Build post_id -> slug mapping
+        slug_map = {}
+        for i, pid in enumerate(post_ids):
+            slug_map[pid] = post_slugs[i] if i < len(post_slugs) else ""
+
+        batch = await services.calendar.confirmed_entries_for_posts(g.s, post_ids)
+        return await render_template(
+            "fragments/container_cards_entries.html",
+            batch=batch, post_ids=post_ids, slug_map=slug_map,
+        )
+
+    _handlers["container-cards"] = _container_cards_handler
+
     bp._fragment_handlers = _handlers
 
     return bp