Rebrand sexp → sx across web platform (173 files)

Rename all sexp directories, files, identifiers, and references to sx.
artdag/ excluded (separate media processing DSL).

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

account/sx/dashboard.sx

@@ -0,0 +1,48 @@
+;; Account dashboard components
+
+(defcomp ~account-error-banner (&key error)
+  (when error
+    (div :class "rounded-lg border border-red-200 bg-red-50 text-red-800 px-4 py-3 text-sm"
+      error)))
+
+(defcomp ~account-user-email (&key email)
+  (when email
+    (p :class "text-sm text-stone-500 mt-1" email)))
+
+(defcomp ~account-user-name (&key name)
+  (when name
+    (p :class "text-sm text-stone-600" name)))
+
+(defcomp ~account-logout-form (&key csrf-token)
+  (form :action "/auth/logout/" :method "post"
+    (input :type "hidden" :name "csrf_token" :value csrf-token)
+    (button :type "submit"
+      :class "inline-flex items-center gap-2 rounded-full border border-stone-300 px-4 py-2 text-sm font-medium text-stone-700 hover:bg-stone-50 transition"
+      (i :class "fa-solid fa-right-from-bracket text-xs") " Sign out")))
+
+(defcomp ~account-label-item (&key name)
+  (span :class "inline-flex items-center rounded-full border border-stone-200 px-3 py-1 text-xs font-medium bg-white/60"
+    name))
+
+(defcomp ~account-labels-section (&key items)
+  (when items
+    (div
+      (h2 :class "text-base font-semibold tracking-tight mb-3" "Labels")
+      (div :class "flex flex-wrap gap-2" items))))
+
+(defcomp ~account-main-panel (&key error email name logout labels)
+  (div :class "w-full max-w-3xl mx-auto px-4 py-6"
+    (div :class "bg-white/70 backdrop-blur rounded-2xl shadow border border-stone-200 p-6 sm:p-8 space-y-8"
+      error
+      (div :class "flex items-center justify-between"
+        (div
+          (h1 :class "text-xl font-semibold tracking-tight" "Account")
+          email
+          name)
+        logout)
+      labels)))
+
+;; Header child wrapper
+(defcomp ~account-header-child (&key inner)
+  (div :id "root-header-child" :class "flex flex-col w-full items-center"
+    inner))