Fix JIT nil-param crash: guard execute-request, restore error logging

- orchestration.sx: add nil guard for verb/url before calling do-fetch
  (prevents "Expected string, got nil" when verb info dict lacks method)
- sx_browser.ml: restore JIT error logging (Eval_error only, not all
  exceptions) so real failures are visible, silence routine fallbacks
- Rebuild WASM bundle with fixes

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

hosts/ocaml/browser/sx_browser.ml

@@ -582,9 +582,9 @@ let () =
       (match l.l_compiled with
        | Some cl when not (Sx_vm.is_jit_failed cl) ->
          (try Some (Sx_vm.call_closure cl args cl.vm_env_ref)
-          with e ->
+          with Eval_error msg ->
             let fn_name = match l.l_name with Some n -> n | None -> "?" in
-            Printf.eprintf "[jit] DISABLED %s — %s\n%!" fn_name (Printexc.to_string e);
+            Printf.eprintf "[jit] DISABLED %s — %s\n%!" fn_name msg;
             l.l_compiled <- Some Sx_vm.jit_failed_sentinel;
             None)
        | Some _ -> None
@@ -595,18 +595,14 @@ let () =
            let globals = env_to_vm_globals global_env in
            let compiled = Sx_vm.jit_compile_lambda l globals in
            _jit_compiling := false;
-           let fn_name = match l.l_name with Some n -> n | None -> "?" in
            (match compiled with
            | Some cl ->
              l.l_compiled <- Some cl;
              (try Some (Sx_vm.call_closure cl args cl.vm_env_ref)
-              with e ->
+              with _ ->
-                Printf.eprintf "[jit] DISABLED %s — %s\n%!" fn_name (Printexc.to_string e);
                 l.l_compiled <- Some Sx_vm.jit_failed_sentinel;
                 None)
-           | None ->
+           | None -> None)
-             Printf.eprintf "[jit] FAIL %s\n%!" fn_name;
-             None)
          end)
     | _ -> None)
 

shared/static/wasm/sx/orchestration.sx

@@ -97,7 +97,7 @@
                 (if (and prompt-msg (nil? prompt-val))
                   (promise-resolve nil)
                   ;; Validation gate
-                  (if (not (validate-for-request el))
+                  (if (or (nil? verb) (nil? url) (not (validate-for-request el)))
                     (promise-resolve nil)
                     (do-fetch el verb verb url
                       (if prompt-val

shared/static/wasm/sx_browser.bc.wasm.js

@@ -1792,7 +1792,7 @@
             blake2_js_for_wasm_create: blake2_js_for_wasm_create};
    }
    (globalThis))
-({"link":[["runtime-0db9b496",0],["prelude-d7e4b000",0],["stdlib-23ce0836",[]],["sx-ea36a0db",[2]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,4]],["dune__exe__Sx_browser-cafa954c",[2,3,5]],["std_exit-10fb8830",[2]],["start-29cf9a72",0]],"generated":(b=>{var
+({"link":[["runtime-0db9b496",0],["prelude-d7e4b000",0],["stdlib-23ce0836",[]],["sx-ea36a0db",[2]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,4]],["dune__exe__Sx_browser-8f530291",[2,3,5]],["std_exit-10fb8830",[2]],["start-29cf9a72",0]],"generated":(b=>{var
 c=b,a=b?.module?.export||b;return{"env":{"caml_ba_kind_of_typed_array":()=>{throw new
 Error("caml_ba_kind_of_typed_array not implemented")},"caml_exn_with_js_backtrace":()=>{throw new
 Error("caml_exn_with_js_backtrace not implemented")},"caml_int64_create_lo_mi_hi":()=>{throw new

web/orchestration.sx

@@ -97,7 +97,7 @@
                 (if (and prompt-msg (nil? prompt-val))
                   (promise-resolve nil)
                   ;; Validation gate
-                  (if (not (validate-for-request el))
+                  (if (or (nil? verb) (nil? url) (not (validate-for-request el)))
                     (promise-resolve nil)
                     (do-fetch el verb verb url
                       (if prompt-val