Wire transpiled VM as active execute_module — 2644 tests pass

The transpiled VM (sx_vm_ref.ml, from lib/vm.sx) is now the ACTIVE
bytecode execution engine. sx_server.ml and sx_browser.ml call
Sx_vm_ref.execute_module instead of Sx_vm.execute_module.

Results:
- OCaml tests: 2644 passed, 0 failed
- WASM tests: 32 passed, 0 failed
- Browser: zero errors, zero warnings, islands hydrate
- Server: pages render, JIT compiles, all routes work

The VM logic now lives in ONE place: lib/vm.sx (SX).
OCaml gets it via transpilation (bootstrap_vm.py).
JS/browser gets it via bytecode compilation (compile-modules.js).

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

hosts/ocaml/bin/sx_server.ml

@@ -1338,7 +1338,7 @@ let rec dispatch env cmd =
     (try
       let code = Sx_vm.code_from_value code_val in
       let globals = env_to_vm_globals env in
-      let result = Sx_vm.execute_module code globals in
+      let result = Sx_vm_ref.execute_module code globals in
       send_ok_value result
     with
     | Eval_error msg -> send_error msg
@@ -1353,7 +1353,7 @@ let rec dispatch env cmd =
       let code = Sx_vm.code_from_value code_val in
       (* VM uses the LIVE kernel env — defines go directly into it *)
       let globals = env_to_vm_globals env in
-      let _result = Sx_vm.execute_module code globals in
+      let _result = Sx_vm_ref.execute_module code globals in
       (* Copy defines back into env *)
       Hashtbl.iter (fun k v -> Hashtbl.replace env.bindings (Sx_types.intern k) v) globals;
       send_ok ()
@@ -1950,7 +1950,7 @@ let http_inject_shell_statics env static_dir sx_sxc =
   let component_hash = Digest.string component_defs |> Digest.to_hex in
   (* Compute per-file hashes for cache busting *)
   let wasm_hash = file_hash (static_dir ^ "/wasm/sx_browser.bc.wasm.js") in
-  let platform_hash = file_hash (static_dir ^ "/wasm/sx-platform-2.js") in
+  let platform_hash = file_hash (static_dir ^ "/wasm/sx-platform.js") in
   let sxbc_hash = sxbc_combined_hash (static_dir ^ "/wasm") in
   (* Read CSS for inline injection *)
   let css_file_names = get_app_list "css-files" ["basics.css"; "tw.css"] in