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>

test/sexp/dashboard.sexpr

@@ -19,11 +19,11 @@
 
 (defcomp ~test-filter-card (&key href label count colour-border colour-bg colour-text active)
   (a :href href
-     :hx-get href
-     :hx-target "#main-panel"
-     :hx-select "#main-panel"
-     :hx-swap "outerHTML"
-     :hx-push-url "true"
+     :sx-get href
+     :sx-target "#main-panel"
+     :sx-select "#main-panel"
+     :sx-swap "outerHTML"
+     :sx-push-url "true"
      :class (str "block rounded border p-3 text-center transition-colors no-underline hover:opacity-80 "
                  colour-border " " colour-bg " "
                  (if active "ring-2 ring-offset-1 ring-stone-500 " ""))
@@ -79,11 +79,11 @@
               "bg-orange-50"))))
     (td :class "px-3 py-2 text-sm font-mono text-stone-700 max-w-0 truncate" :title nodeid
       (a :href (str "/test/" nodeid)
-         :hx-get (str "/test/" nodeid)
-         :hx-target "#main-panel"
-         :hx-select "#main-panel"
-         :hx-swap "outerHTML"
-         :hx-push-url "true"
+         :sx-get (str "/test/" nodeid)
+         :sx-target "#main-panel"
+         :sx-select "#main-panel"
+         :sx-swap "outerHTML"
+         :sx-push-url "true"
          :class "hover:underline hover:text-sky-600"
         nodeid))
     (td :class "px-3 py-2 text-center"
@@ -97,7 +97,7 @@
     (td :class "px-3 py-2 text-sm text-rose-600 font-mono max-w-xs truncate" :title longrepr
       (when longrepr longrepr))))
 
-(defcomp ~test-results-table (&key rows-html has-failures)
+(defcomp ~test-results-table (&key rows has-failures)
   (div :class "overflow-x-auto rounded border border-stone-200 bg-white"
     (table :class "w-full text-left"
       (thead
@@ -106,7 +106,7 @@
           (th :class "px-3 py-2 text-xs font-medium text-stone-600 text-center w-24" "Status")
           (th :class "px-3 py-2 text-xs font-medium text-stone-600 text-right w-20" "Time")
           (th :class "px-3 py-2 text-xs font-medium text-stone-600 w-48" "Error")))
-      (tbody (raw! rows-html)))))
+      (tbody (when rows rows)))))
 
 (defcomp ~test-running-indicator ()
   (div :class "flex items-center justify-center py-12 text-stone-500"
@@ -124,11 +124,11 @@
   (div :class "space-y-6 p-4"
     (div :class "flex items-center gap-3"
       (a :href "/"
-         :hx-get "/"
-         :hx-target "#main-panel"
-         :hx-select "#main-panel"
-         :hx-swap "outerHTML"
-         :hx-push-url "true"
+         :sx-get "/"
+         :sx-target "#main-panel"
+         :sx-select "#main-panel"
+         :sx-swap "outerHTML"
+         :sx-push-url "true"
          :class "text-sky-600 hover:text-sky-800 text-sm"
         "← Back to results")
       (span :class (str "inline-flex items-center rounded-full border px-2 py-0.5 text-xs font-medium "