sx-http: fix homepage (bare symbol → fn call) + auto-quote slugs + resilient SSR

Homepage fix: path_expr "home" was evaluated as a symbol lookup (returning
the Lambda) instead of a function call. Now wraps bare symbols in a list:
home → (home) → calls the page function → returns component call.

Slug routing: auto_quote converts unknown symbols to strings before eval.
(etc (plan sx-host)) → (etc (plan "sx-host")) — resolves nested slug URLs.

Resilient SSR: render_to_buf catches Eval_error per-element and continues
rendering. Partial SSR output preserved even when some elements fail.

WASM kernel rebuilt (define shorthand + island placeholder changes).

Remaining: WASM kernel "Undefined symbol: let" — pre-existing bug in
client-side component-defs parsing. (list let ...) triggers symbol lookup
instead of special form recognition. Affects island hydration on all pages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

hosts/ocaml/bin/sx_server.ml

@@ -1462,12 +1462,29 @@ let http_render_page env path =
       String.map (fun c -> if c = '.' then ' ' else c) p
     end
   in
+  (* Auto-quote unknown symbols as strings (slug parameters).
+     e.g. (etc (plan sx-host)) → (etc (plan "sx-host"))
+     Matches Python's prepare_url_expr behavior. *)
+  let rec auto_quote expr =
+    match expr with
+    | Symbol s when not (env_has env s) && (try ignore (Sx_primitives.get_primitive s); false with _ -> true) ->
+      String s
+    | List items -> List (List.map auto_quote items)
+    | ListRef { contents = items } -> List (List.map auto_quote items)
+    | _ -> expr
+  in
   (* Evaluate page function to get component call *)
   let page_ast =
     try
       let exprs = Sx_parser.parse_all path_expr in
       let expr = match exprs with [e] -> e | _ -> List exprs in
-      Sx_ref.eval_expr expr (Env env)
+      let quoted = auto_quote expr in
+      (* Bare symbols (like "home") → wrap in list to call as function.
+         e.g. home → (home), geography → (geography) *)
+      let callable = match quoted with
+        | Symbol _ -> List [quoted]
+        | _ -> quoted in
+      Sx_ref.eval_expr callable (Env env)
     with e ->
       Printf.eprintf "[http-route] eval failed for '%s': %s\n%!" path_expr (Printexc.to_string e);
       Nil
@@ -1503,7 +1520,10 @@ let http_render_page env path =
         let body_exprs = Sx_parser.parse_all body_str in
         let body_expr = match body_exprs with
           | [e] -> e | [] -> Nil | _ -> List (Symbol "<>" :: body_exprs) in
-        Sx_render.render_to_html_streaming body_expr env
+        let buf = Buffer.create 65536 in
+        (try Sx_render.render_to_buffer buf body_expr env
+         with e -> Printf.eprintf "[http-ssr] partial: %s\n%!" (Printexc.to_string e));
+        Buffer.contents buf
       with e ->
         Printf.eprintf "[http-ssr] failed: %s\n%!" (Printexc.to_string e); ""
     in

hosts/ocaml/lib/sx_render.ml

@@ -266,9 +266,7 @@ and render_list_to_html head args env =
        | _ ->
          let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
          do_render_to_html result env)
-    with Eval_error _ ->
-      let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
-      do_render_to_html result env)
+    with Eval_error _ -> "")
   | _ ->
     let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
     do_render_to_html result env
@@ -513,12 +511,16 @@ and render_list_buf buf head args env =
        | _ ->
          let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
          render_to_buf buf result env)
-    with Eval_error _ ->
-      let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
-      render_to_buf buf result env)
+    with Eval_error msg ->
+      (* Unknown symbol/component — skip silently during SSR.
+         The client will render from page-sx. *)
+      Printf.eprintf "[ssr-skip] %s\n%!" msg)
   | _ ->
-    let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
-    render_to_buf buf result env
+    (try
+      let result = Sx_ref.eval_expr (List (head :: args)) (Env env) in
+      render_to_buf buf result env
+    with Eval_error msg ->
+      Printf.eprintf "[ssr-skip] %s\n%!" msg)
 
 and render_element_buf buf tag args env =
   let (attrs, children) = parse_element_args args env in