Fix: local bindings now shadow HTML tag special forms in browser evaluator

Root cause: sx_browser.ml registered all HTML tags (a, b, i, p, s, u, g, etc.)
as custom special forms. The evaluator's step_eval_list checked custom special
forms BEFORE checking local env bindings. So (let ((a (fn () 42))) (a))
matched the HTML tag <a> instead of calling the local function a.

Fix: skip custom special forms AND render-check when the symbol is bound in
the local env. Added (not (env-has? env name)) guard to both checks in
step-eval-list (spec/evaluator.sx and transpiled sx_ref.ml).

This was the root cause of "[sx] resume: Not callable: nil" — after hs-wait
resumed, calling letrec-bound functions like wait-boot (which is not an HTML
tag) worked, but any function whose name collided with an HTML tag failed.

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

shared/static/wasm/sx/hs-integration.sxbc

@@ -1,3 +1,3 @@
 (sxbc 1 "99bd2816b1cd7891"
   (code
-    :constants ("hs-handler" {:upvalue-count 0 :arity 1 :constants ("hs-to-sx-from-source" "eval-expr-cek" "list" fn me let it event) :bytecode (20 0 0 16 0 48 1 17 1 20 1 0 1 3 0 1 4 0 52 2 0 1 1 5 0 1 6 0 2 52 2 0 2 1 7 0 2 52 2 0 2 52 2 0 2 16 1 52 2 0 3 52 2 0 3 49 1 50)} "hs-activate!" {:upvalue-count 0 :arity 1 :constants ("dom-get-attr" "_" "not" "dom-get-data" "hs-active" "dom-set-data" "hs-handler") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 16 1 6 33 15 0 5 20 3 0 16 0 1 4 0 48 2 52 2 0 1 33 30 0 20 5 0 16 0 1 4 0 3 48 3 5 20 6 0 16 1 48 1 17 2 16 2 16 0 49 1 32 1 0 2 50)} "hs-boot!" {:upvalue-count 0 :arity 0 :constants ("dom-query-all" "host-get" "host-global" "document" "body" "[_]" "for-each" {:upvalue-count 0 :arity 1 :constants ("hs-activate!") :bytecode (20 0 0 16 0 49 1 50)}) :bytecode (20 0 0 20 1 0 20 2 0 1 3 0 48 1 1 4 0 48 2 1 5 0 48 2 17 0 51 7 0 16 0 52 6 0 2 50)} "hs-boot-subtree!" {:upvalue-count 0 :arity 1 :constants ("dom-query-all" "[_]" "for-each" {:upvalue-count 0 :arity 1 :constants ("hs-activate!") :bytecode (20 0 0 16 0 49 1 50)} "dom-get-attr" "_" "hs-activate!") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 51 3 0 16 1 52 2 0 2 5 20 4 0 16 0 1 5 0 48 2 33 10 0 20 6 0 16 0 49 1 32 1 0 2 50)}) :bytecode (51 1 0 128 0 0 5 51 3 0 128 2 0 5 51 5 0 128 4 0 5 51 7 0 128 6 0 50)))
+    :constants ("hs-handler" {:upvalue-count 0 :arity 1 :constants ("hs-to-sx-from-source" "eval-expr-cek" "list" fn me let it event) :bytecode (20 0 0 16 0 48 1 17 1 20 1 0 1 3 0 1 4 0 52 2 0 1 1 5 0 1 6 0 2 52 2 0 2 1 7 0 2 52 2 0 2 52 2 0 2 16 1 52 2 0 3 52 2 0 3 49 1 50)} "hs-activate!" {:upvalue-count 0 :arity 1 :constants ("dom-get-attr" "_" "not" "dom-get-data" "hs-active" "dom-set-data" "hs-handler") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 16 1 6 33 15 0 5 20 3 0 16 0 1 4 0 48 2 52 2 0 1 33 30 0 20 5 0 16 0 1 4 0 3 48 3 5 20 6 0 16 1 48 1 17 2 16 2 16 0 49 1 32 1 0 2 50)} "hs-boot!" {:upvalue-count 0 :arity 0 :constants ("dom-query-all" "host-get" "host-global" "document" "body" "[_]" "for-each" {:upvalue-count 0 :arity 1 :constants ("hs-activate!") :bytecode (20 0 0 16 0 49 1 50)}) :bytecode (20 0 0 1 3 0 52 2 0 1 1 4 0 52 1 0 2 1 5 0 48 2 17 0 51 7 0 16 0 52 6 0 2 50)} "hs-boot-subtree!" {:upvalue-count 0 :arity 1 :constants ("dom-query-all" "[_]" "for-each" {:upvalue-count 0 :arity 1 :constants ("hs-activate!") :bytecode (20 0 0 16 0 49 1 50)} "dom-get-attr" "_" "hs-activate!") :bytecode (20 0 0 16 0 1 1 0 48 2 17 1 51 3 0 16 1 52 2 0 2 5 20 4 0 16 0 1 5 0 48 2 33 10 0 20 6 0 16 0 49 1 32 1 0 2 50)}) :bytecode (51 1 0 128 0 0 5 51 3 0 128 2 0 5 51 5 0 128 4 0 5 51 7 0 128 6 0 50)))

shared/static/wasm/sx/module-manifest.json

@@ -1006,6 +1006,7 @@
       "hs-last",
       "hs-repeat-times",
       "hs-repeat-forever",
+      "hs-repeat-while",
       "hs-fetch",
       "hs-coerce",
       "hs-add",

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",[]],["re-9a0de245",[2]],["sx-875d5bae",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-def18509",[2,4,6]],["std_exit-10fb8830",[2]],["start-f808dbe1",0]],"generated":(b=>{var
+({"link":[["runtime-0db9b496",0],["prelude-d7e4b000",0],["stdlib-23ce0836",[]],["re-9a0de245",[2]],["sx-624c0574",[2,3]],["jsoo_runtime-f96b44a8",[2]],["js_of_ocaml-651f6707",[2,5]],["dune__exe__Sx_browser-def18509",[2,4,6]],["std_exit-10fb8830",[2]],["start-f808dbe1",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