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>

orders/sexp/checkout.sexpr

@@ -6,27 +6,27 @@
     (p :class "text-xs sm:text-sm text-stone-600" "We tried to start your payment with SumUp but hit a problem.")))
 
 (defcomp ~orders-checkout-error-order-id (&key oid)
-  (p :class "text-xs text-rose-800/80" "Order ID: " (span :class "font-mono" (raw! oid))))
+  (p :class "text-xs text-rose-800/80" "Order ID: " (span :class "font-mono" oid)))
 
 (defcomp ~orders-checkout-error-pay-btn (&key url)
   (a :href url :class "inline-flex items-center px-3 py-2 text-xs sm:text-sm rounded-full border border-emerald-600 bg-emerald-600 text-white hover:bg-emerald-700 transition"
     (i :class "fa fa-credit-card mr-2" :aria-hidden "true") "Open payment page"))
 
-(defcomp ~orders-checkout-error-content (&key msg order-html back-url)
+(defcomp ~orders-checkout-error-content (&key msg order back-url)
   (div :class "max-w-full px-3 py-3 space-y-4"
     (div :class "rounded-2xl border border-rose-200 bg-rose-50/80 p-4 sm:p-6 text-sm text-rose-900 space-y-2"
       (p :class "font-medium" "Something went wrong.")
-      (p (raw! msg))
-      (raw! order-html))
+      (p msg)
+      order)
     (div
       (a :href back-url
         :class "inline-flex items-center px-3 py-2 text-xs sm:text-sm rounded-full border border-stone-300 bg-white hover:bg-stone-50 transition"
         (i :class "fa fa-shopping-cart mr-2" :aria-hidden "true") "Back to cart"))))
 
-(defcomp ~orders-detail-filter (&key created status list-url recheck-url csrf pay-html)
+(defcomp ~orders-detail-filter (&key created status list-url recheck-url csrf pay)
   (header :class "mb-6 sm:mb-8 flex flex-col sm:flex-row sm:items-center justify-between gap-3 sm:gap-4"
     (div :class "space-y-1"
-      (p :class "text-xs sm:text-sm text-stone-600" "Placed " (raw! created) " \u00b7 Status: " (raw! status)))
+      (p :class "text-xs sm:text-sm text-stone-600" "Placed " created " \u00b7 Status: " status))
     (div :class "flex w-full sm:w-auto justify-start sm:justify-end gap-2"
       (a :href list-url :class "inline-flex items-center px-3 py-2 text-xs sm:text-sm rounded-full border border-stone-300 bg-white hover:bg-stone-50 transition"
         (i :class "fa-solid fa-list mr-2" :aria-hidden "true") "All orders")
@@ -35,4 +35,4 @@
         (button :type "submit"
           :class "inline-flex items-center px-3 py-2 text-xs sm:text-sm rounded-full border border-stone-300 bg-white hover:bg-stone-50 transition"
           (i :class "fa-solid fa-rotate mr-2" :aria-hidden "true") "Re-check status"))
-      (raw! pay-html))))
+      pay)))