Add build-all.sh, bytecode test mode — 5 failures with SX_TEST_BYTECODE=1

The hydration bug root cause: .sxbc bytecoded modules break effect
closures. Source-loaded modules work (15/15), bytecoded fail (10/15).

Run: SX_TEST_BYTECODE=1 node hosts/ocaml/browser/test_wasm_native.js

Failing: scoped static class, signal attr initial, reactive-spread,
CSSX in island scope, reactive attr update.

Also adds build-all.sh (full WASM pipeline) and sx_build target="wasm"
MCP tool integration.

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

hosts/ocaml/browser/build-all.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+# Full build: OCaml WASM kernel + bundle + bytecode compile + deploy to shared/static/wasm/
+#
+# Usage: bash hosts/ocaml/browser/build-all.sh
+#   Or via MCP: sx_build target="wasm"
+set -e
+cd "$(dirname "$0")"
+
+echo "=== 1. Build WASM kernel ==="
+# Remove assets dir that conflicts with dune's output target
+rm -rf sx_browser.bc.wasm.assets
+eval $(opam env 2>/dev/null)
+cd ..
+dune build browser/sx_browser.bc.wasm.js browser/sx_browser.bc.js bin/sx_server.exe 2>&1
+cd browser
+
+echo "=== 2. Bundle ==="
+bash bundle.sh
+
+echo "=== 3. Compile .sxbc bytecode ==="
+node compile-modules.js dist
+
+echo "=== 4. Deploy to shared/static/wasm/ ==="
+DEST=../../../shared/static/wasm
+cp dist/sx_browser.bc.wasm.js "$DEST/"
+cp dist/sx_browser.bc.js "$DEST/"
+rm -rf "$DEST/sx_browser.bc.wasm.assets"
+cp -r dist/sx_browser.bc.wasm.assets "$DEST/"
+cp dist/sx/*.sx "$DEST/sx/"
+cp dist/sx/*.sxbc "$DEST/sx/" 2>/dev/null || true
+# Keep assets dir for Node.js WASM tests
+cp -r dist/sx_browser.bc.wasm.assets ./ 2>/dev/null || true
+
+echo "=== 5. Run WASM tests ==="
+node test_wasm_native.js
+
+echo "=== Done ==="

hosts/ocaml/browser/bundle.sh

@@ -65,8 +65,8 @@ cp "$ROOT/web/engine.sx"        "$DIST/sx/"
 cp "$ROOT/web/orchestration.sx" "$DIST/sx/"
 cp "$ROOT/web/boot.sx"          "$DIST/sx/"
 
-# 9. CSSX (stylesheet language)
-cp "$ROOT/sx/sx/cssx.sx"        "$DIST/sx/"
+# 9. CSSX (stylesheet language — runtime with tw, ~cssx/tw, cssx-process-token etc.)
+cp "$ROOT/shared/sx/templates/cssx.sx" "$DIST/sx/"
 
 # Summary
 WASM_SIZE=$(du -sh "$DIST/sx_browser.bc.wasm.assets" | cut -f1)

hosts/ocaml/browser/compile-modules.js

@@ -42,6 +42,7 @@ const FILES = [
   'harness-web.sx', 'engine.sx', 'orchestration.sx', 'boot.sx',
 ];
 
+
 // ---------------------------------------------------------------------------
 // Build the full input script — all commands in one batch
 // ---------------------------------------------------------------------------

hosts/ocaml/browser/test_wasm_native.js

@@ -196,6 +196,12 @@ async function main() {
     K.eval('(do (define test-set-attr (fn (el name val) (effect (fn () (dom-set-attr el name val))))) (let ((el (dom-create-element "div" nil))) (test-set-attr el "class" "from-define") (dom-get-attr el "class")))'),
     'from-define');
 
+  // Verify the effect body ACTUALLY EXECUTES (not just returning a value).
+  // In browser WASM, the effect body silently doesn't run.
+  assert('define+effect body executes',
+    K.eval('(do (define test-fx-log (fn (el log) (effect (fn () (append! log "ran") (dom-set-attr el "class" "fx"))))) (let ((el (dom-create-element "div" nil)) (log (list))) (test-fx-log el log) (str (len log) ":" (first log))))'),
+    '1:ran');
+
   // Same thing with let works (proves it's define-specific)
   assert('let+effect+host-obj',
     K.eval('(let ((test-set-attr (fn (el name val) (effect (fn () (dom-set-attr el name val)))))) (let ((el (dom-create-element "div" nil))) (test-set-attr el "class" "from-let") (dom-get-attr el "class")))'),