Add sx documentation app (sx.rose-ash.com)

New public-facing service documenting the s-expression rendering engine.
Modelled on four.htmx.org with violet theme, all content rendered via sx.

Sections: docs, reference, protocols, examples (live demos), essays
(including "sx sucks"). No database — purely static documentation.

Port 8012, Redis DB 10. CI and deploy.sh updated with app_dir() mapping
for sx_docs -> sx/ directory. Caddy reverse proxy entry added separately.

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

sx/sxc/home.sx

@@ -0,0 +1,66 @@
+;; SX docs — home page components
+
+(defcomp ~sx-hero ()
+  (div :class "max-w-4xl mx-auto px-6 py-16 text-center"
+    (h1 :class "text-5xl font-bold text-stone-900 mb-4"
+      (span :class "text-violet-600" "sx"))
+    (p :class "text-2xl text-stone-600 mb-8"
+      "High power tools for HTML — with s-expressions")
+    (p :class "text-lg text-stone-500 max-w-2xl mx-auto mb-12"
+      "A hypermedia-driven UI engine that combines htmx's server-first philosophy "
+      "with React's component model. All rendered via s-expressions over the wire.")
+    (div :class "bg-stone-900 rounded-lg p-6 text-left font-mono text-sm overflow-x-auto"
+      (pre :class "text-stone-300"
+        (code :class "language-lisp"
+          "(defcomp ~greeting (&key name)\n  (div :class \"p-4 rounded bg-violet-50\"\n    (h2 :class \"text-lg font-bold\"\n      (str \"Hello, \" name \"!\"))\n    (button\n      :sx-get \"/api/greet\"\n      :sx-target \"closest div\"\n      :sx-swap \"outerHTML\"\n      :class \"mt-2 px-4 py-2 bg-violet-600 text-white rounded\"\n      \"Refresh\")))")))))
+
+(defcomp ~sx-philosophy ()
+  (div :class "max-w-4xl mx-auto px-6 py-12"
+    (h2 :class "text-3xl font-bold text-stone-900 mb-8" "Design philosophy")
+    (div :class "grid md:grid-cols-2 gap-8"
+      (div :class "space-y-4"
+        (h3 :class "text-xl font-semibold text-violet-700" "From htmx")
+        (ul :class "space-y-2 text-stone-600"
+          (li "Server-rendered HTML over the wire")
+          (li "Hypermedia attributes on any element (sx-get, sx-post, ...)")
+          (li "Target/swap model for partial page updates")
+          (li "No client-side routing, no virtual DOM")
+          (li "Progressive enhancement — works without JS (mostly)")))
+      (div :class "space-y-4"
+        (h3 :class "text-xl font-semibold text-violet-700" "From React")
+        (ul :class "space-y-2 text-stone-600"
+          (li "Composable components with defcomp")
+          (li "Client-side rendering from s-expression source")
+          (li "Component caching via localStorage + hash invalidation")
+          (li "On-demand CSS — only ship what's used")
+          (li "DOM morphing for smooth history navigation"))))))
+
+(defcomp ~sx-how-it-works ()
+  (div :class "max-w-4xl mx-auto px-6 py-12"
+    (h2 :class "text-3xl font-bold text-stone-900 mb-8" "How it works")
+    (div :class "space-y-6"
+      (div :class "flex items-start gap-4"
+        (div :class "flex-shrink-0 w-8 h-8 rounded-full bg-violet-100 text-violet-700 flex items-center justify-center font-bold" "1")
+        (div
+          (h3 :class "font-semibold text-stone-900" "Server renders sx")
+          (p :class "text-stone-600" "Python builds s-expression trees. Components, HTML elements, data — all in one format.")))
+      (div :class "flex items-start gap-4"
+        (div :class "flex-shrink-0 w-8 h-8 rounded-full bg-violet-100 text-violet-700 flex items-center justify-center font-bold" "2")
+        (div
+          (h3 :class "font-semibold text-stone-900" "Wire sends text/sx")
+          (p :class "text-stone-600" "Responses are s-expression source code with content type text/sx. Component definitions cached client-side.")))
+      (div :class "flex items-start gap-4"
+        (div :class "flex-shrink-0 w-8 h-8 rounded-full bg-violet-100 text-violet-700 flex items-center justify-center font-bold" "3")
+        (div
+          (h3 :class "font-semibold text-stone-900" "Client evaluates + renders")
+          (p :class "text-stone-600" "sx.js parses, evaluates, and renders to DOM. Same evaluator runs server-side (Python) and client-side (JS)."))))))
+
+(defcomp ~sx-credits ()
+  (div :class "max-w-4xl mx-auto px-6 py-12 border-t border-stone-200"
+    (p :class "text-stone-500 text-sm"
+      "sx is heavily inspired by "
+      (a :href "https://htmx.org" :class "text-violet-600 hover:underline" "htmx")
+      " by Carson Gross. This documentation site is modelled on "
+      (a :href "https://four.htmx.org" :class "text-violet-600 hover:underline" "four.htmx.org")
+      ". htmx showed that HTML is the right hypermedia format. "
+      "sx takes that idea and wraps it in parentheses.")))