feat(web): NetX workbench, UME-only UI, i18n, and header status

- Replace sidebar app with workbench home and module tabs (openOrFocusModule)

- Remove legacy pages; add module registry, shared tab channel, WEB.md

- Add zh/en i18n, global ToastProvider, restore oclaw bridge pill in header

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/components/HelpHint.tsx

@@ -0,0 +1,46 @@
+import { useEffect, useRef, useState } from "react";
+
+type Props = {
+  text: string;
+  ariaLabel: string;
+};
+
+export function HelpHint({ text, ariaLabel }: Props) {
+  const [open, setOpen] = useState(false);
+  const rootRef = useRef<HTMLSpanElement>(null);
+
+  useEffect(() => {
+    if (!open) return;
+    const onDocClick = (ev: MouseEvent) => {
+      if (!rootRef.current?.contains(ev.target as Node)) setOpen(false);
+    };
+    const onKey = (ev: KeyboardEvent) => {
+      if (ev.key === "Escape") setOpen(false);
+    };
+    document.addEventListener("mousedown", onDocClick);
+    document.addEventListener("keydown", onKey);
+    return () => {
+      document.removeEventListener("mousedown", onDocClick);
+      document.removeEventListener("keydown", onKey);
+    };
+  }, [open]);
+
+  return (
+    <span className="help-hint" ref={rootRef}>
+      <button
+        type="button"
+        className="help-hint__trigger"
+        aria-label={ariaLabel}
+        aria-expanded={open}
+        onClick={() => setOpen((v) => !v)}
+      >
+        ?
+      </button>
+      {open ? (
+        <div className="help-hint__popover" role="tooltip">
+          {text}
+        </div>
+      ) : null}
+    </span>
+  );
+}