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>

docker-compose.dev.yml

@@ -45,6 +45,7 @@ services:
       - ./blog/alembic.ini:/app/blog/alembic.ini:ro
       - ./blog/alembic:/app/blog/alembic:ro
       - ./blog/app.py:/app/app.py
+      - ./blog/sexp_components.py:/app/sexp_components.py
       - ./blog/bp:/app/bp
       - ./blog/services:/app/services
       - ./blog/templates:/app/templates
@@ -82,6 +83,7 @@ services:
       - ./market/alembic.ini:/app/market/alembic.ini:ro
       - ./market/alembic:/app/market/alembic:ro
       - ./market/app.py:/app/app.py
+      - ./market/sexp_components.py:/app/sexp_components.py
       - ./market/bp:/app/bp
       - ./market/services:/app/services
       - ./market/templates:/app/templates
@@ -118,6 +120,7 @@ services:
       - ./cart/alembic.ini:/app/cart/alembic.ini:ro
       - ./cart/alembic:/app/cart/alembic:ro
       - ./cart/app.py:/app/app.py
+      - ./cart/sexp_components.py:/app/sexp_components.py
       - ./cart/bp:/app/bp
       - ./cart/services:/app/services
       - ./cart/templates:/app/templates
@@ -154,6 +157,7 @@ services:
       - ./events/alembic.ini:/app/events/alembic.ini:ro
       - ./events/alembic:/app/events/alembic:ro
       - ./events/app.py:/app/app.py
+      - ./events/sexp_components.py:/app/sexp_components.py
       - ./events/bp:/app/bp
       - ./events/services:/app/services
       - ./events/templates:/app/templates
@@ -190,6 +194,7 @@ services:
       - ./federation/alembic.ini:/app/federation/alembic.ini:ro
       - ./federation/alembic:/app/federation/alembic:ro
       - ./federation/app.py:/app/app.py
+      - ./federation/sexp_components.py:/app/sexp_components.py
       - ./federation/bp:/app/bp
       - ./federation/services:/app/services
       - ./federation/templates:/app/templates
@@ -226,6 +231,7 @@ services:
       - ./account/alembic.ini:/app/account/alembic.ini:ro
       - ./account/alembic:/app/account/alembic:ro
       - ./account/app.py:/app/app.py
+      - ./account/sexp_components.py:/app/sexp_components.py
       - ./account/bp:/app/bp
       - ./account/services:/app/services
       - ./account/templates:/app/templates
@@ -324,6 +330,7 @@ services:
       - ./orders/alembic.ini:/app/orders/alembic.ini:ro
       - ./orders/alembic:/app/orders/alembic:ro
       - ./orders/app.py:/app/app.py
+      - ./orders/sexp_components.py:/app/sexp_components.py
       - ./orders/bp:/app/bp
       - ./orders/services:/app/services
       - ./orders/templates:/app/templates