Send all responses as sexp wire format with client-side rendering

- Server sends sexp source text, client (sexp.js) renders everything
- SexpExpr marker class for nested sexp composition in serialize()
- sexp_page() HTML shell with data-mount="body" for full page loads
- sexp_response() returns text/sexp for OOB/partial responses
- ~app-body layout component replaces ~app-layout (no raw!)
- ~rich-text is the only component using raw! (for CMS HTML content)
- Fragment endpoints return text/sexp, auto-wrapped in SexpExpr
- All _*_html() helpers converted to _*_sexp() returning sexp source
- Head auto-hoist: sexp.js moves meta/title/link/script[ld+json]
  from rendered body to document.head automatically
- Unknown components render warning box instead of crashing page
- Component kwargs preserve AST for lazy rendering (fixes <> in kwargs)
- Fix unterminated paren in events/sexp/tickets.sexpr

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

cart/bp/orders/routes.py

@@ -13,6 +13,7 @@ from shared.infrastructure.http_utils import vary as _vary, current_url_without_
 from shared.infrastructure.cart_identity import current_cart_identity
 from bp.cart.services import check_sumup_status
 from shared.browser.app.utils.htmx import is_htmx_request
+from shared.sexp.helpers import sexp_response
 from bp import register_order
 
 from .filters.qs import makeqs_factory, decode
@@ -151,17 +152,18 @@ def register(url_prefix: str) -> Blueprint:
                 ctx, orders, page, total_pages, search, total_count,
                 url_for, qs_fn,
             )
+            resp = await make_response(html)
         elif page > 1:
-            html = await render_orders_rows(
+            sexp_src = await render_orders_rows(
                 ctx, orders, page, total_pages, url_for, qs_fn,
             )
+            resp = sexp_response(sexp_src)
         else:
-            html = await render_orders_oob(
+            sexp_src = await render_orders_oob(
                 ctx, orders, page, total_pages, search, total_count,
                 url_for, qs_fn,
             )
-
-        resp = await make_response(html)
+            resp = sexp_response(sexp_src)
         resp.headers["Hx-Push-Url"] = _current_url_without_page()
         return _vary(resp)