OCaml runtime: R7RS parameters, VM closure introspection, import suspension

- R7RS parameter primitives (make-parameter, parameter?, parameterize support)
- VM closure get_val introspection (vm-code, vm-upvalues, vm-name, vm-globals)
- Lazy list caching on vm_code for transpiled VM performance
- VM import suspension: check_io_suspension + resume_module for browser lazy loading
- 23 new R7RS tests (parameter-basic, parameterize-basic, syntax-rules-basic)
- Playwright bytecode-loading spec + WASM rebuild

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

hosts/ocaml/lib/sx_runtime.ml

@@ -131,6 +131,38 @@ let get_val container key =
      | "frames" -> List (List.map (fun f -> VmFrame f) m.vm_frames)
      | "globals" -> Dict m.vm_globals
      | _ -> Nil)
+  | VmClosure cl, String k ->
+    (match k with
+     | "vm-code" ->
+       (* Return vm_code fields as a Dict.  The bytecode and constants arrays
+          are lazily converted to Lists and cached on the vm_code record so
+          the transpiled VM loop (which re-derives bc/consts each iteration)
+          doesn't allocate on every step. *)
+       let c = cl.vm_code in
+       let bc = match c.vc_bytecode_list with
+         | Some l -> l
+         | None ->
+           let l = Array.to_list (Array.map (fun i -> Number (float_of_int i)) c.vc_bytecode) in
+           c.vc_bytecode_list <- Some l; l in
+       let consts = match c.vc_constants_list with
+         | Some l -> l
+         | None ->
+           let l = Array.to_list c.vc_constants in
+           c.vc_constants_list <- Some l; l in
+       let d = Hashtbl.create 4 in
+       Hashtbl.replace d "vc-bytecode" (List bc);
+       Hashtbl.replace d "vc-constants" (List consts);
+       Hashtbl.replace d "vc-arity" (Number (float_of_int c.vc_arity));
+       Hashtbl.replace d "vc-locals" (Number (float_of_int c.vc_locals));
+       Dict d
+     | "vm-upvalues" ->
+       List (Array.to_list (Array.map (fun uv -> uv.uv_value) cl.vm_upvalues))
+     | "vm-name" ->
+       (match cl.vm_name with Some n -> String n | None -> Nil)
+     | "vm-globals" -> Dict cl.vm_env_ref
+     | "vm-closure-env" ->
+       (match cl.vm_closure_env with Some e -> Env e | None -> Nil)
+     | _ -> Nil)
   | Dict d, String k -> dict_get d k
   | Dict d, Keyword k -> dict_get d k
   | (List l | ListRef { contents = l }), Number n ->