Phase 6: Replace render_template() with s-expression rendering in all GET routes

Migrate ~52 GET route handlers across all 7 services from Jinja
render_template() to s-expression component rendering. Each service
gets a sexp_components.py with page/oob/cards render functions.

- Add per-service sexp_components.py (account, blog, cart, events,
  federation, market, orders) with full page, OOB, and pagination
  card rendering
- Add shared/sexp/helpers.py with call_url, root_header_html,
  full_page, oob_page utilities
- Update all GET routes to use get_template_context() + render fns
- Fix get_template_context() to inject Jinja globals (URL helpers)
- Add qs_filter to base_context for sexp filter URL building
- Mount sexp_components.py in docker-compose.dev.yml for all services
- Import sexp_components in app.py for Hypercorn --reload watching
- Fix route_prefix import (shared.utils not shared.infrastructure.urls)
- Fix federation choose-username missing actor in context
- Fix market page_markets missing post in context

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

blog/bp/admin/routes.py

@@ -29,27 +29,28 @@ def register(url_prefix):
     @bp.get("/")
     @require_admin
     async def home():
+      from shared.sexp.page import get_template_context
+      from sexp_components import render_settings_page, render_settings_oob
 
-      # Determine which template to use based on request type and pagination
+      tctx = await get_template_context()
       if not is_htmx_request():
-          # Normal browser request: full page with layout
-          html = await render_template(
-          "_types/root/settings/index.html",
-      )
-      
+          html = await render_settings_page(tctx)
       else:
-          html = await render_template("_types/root/settings/_oob_elements.html")
-
+          html = await render_settings_oob(tctx)
 
       return await make_response(html)
 
     @bp.get("/cache/")
     @require_admin
     async def cache():
+        from shared.sexp.page import get_template_context
+        from sexp_components import render_cache_page, render_cache_oob
+
+        tctx = await get_template_context()
         if not is_htmx_request():
-            html = await render_template("_types/root/settings/cache/index.html")
+            html = await render_cache_page(tctx)
         else:
-            html = await render_template("_types/root/settings/cache/_oob_elements.html")
+            html = await render_cache_oob(tctx)
         return await make_response(html)
 
     @bp.post("/cache_clear/")