Integrate federation app with shared menu/header system

Replace standalone base.html with the shared _types/root layout.
Social pages get a second nav row via _types/social/index.html.
Root / becomes a blank page with shared chrome. Auth pages use
the shared layout without the social nav bar.

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

app.py

@@ -20,10 +20,22 @@ from bp import (
 async def federation_context() -> dict:
     """Federation app context processor."""
     from shared.infrastructure.context import base_context
+    from shared.services.navigation import get_navigation_tree
+    from shared.infrastructure.cart_identity import current_cart_identity
 
     ctx = await base_context()
 
-    # If user is logged in, check for ActorProfile
+    ctx["menu_items"] = await get_navigation_tree(g.s)
+
+    # Cart data (consistent with all other apps)
+    ident = current_cart_identity()
+    summary = await services.cart.cart_summary(
+        g.s, user_id=ident["user_id"], session_id=ident["session_id"],
+    )
+    ctx["cart_count"] = summary.count + summary.calendar_count + summary.ticket_count
+    ctx["cart_total"] = float(summary.total + summary.calendar_total + summary.ticket_total)
+
+    # Actor profile for logged-in users
     if g.get("user"):
         actor = await services.federation.get_actor_by_user_id(g.s, g.user.id)
         ctx["actor"] = actor
@@ -60,8 +72,7 @@ def create_app() -> "Quart":
     @app.get("/")
     async def home():
         from quart import render_template
-        stats = await services.federation.get_stats(g.s)
-        return await render_template("federation/home.html", stats=stats)
+        return await render_template("_types/federation/index.html")
 
     return app