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/hooks/useToast.tsx

@@ -0,0 +1,44 @@
+import { createContext, useCallback, useContext, useEffect, useMemo, useState, type ReactNode } from "react";
+
+export type ToastState = { type: "ok" | "error"; text: string } | null;
+
+type ToastApi = {
+  toast: ToastState;
+  showOk: (text: string) => void;
+  showError: (text: string) => void;
+  clear: () => void;
+};
+
+const ToastContext = createContext<ToastApi | null>(null);
+
+function useToastState(autoHideMs: number): ToastApi {
+  const [toast, setToast] = useState<ToastState>(null);
+
+  const showOk = useCallback((text: string) => setToast({ type: "ok", text }), []);
+  const showError = useCallback((text: string) => setToast({ type: "error", text }), []);
+  const clear = useCallback(() => setToast(null), []);
+
+  useEffect(() => {
+    if (!toast) return;
+    const timer = window.setTimeout(() => setToast(null), autoHideMs);
+    return () => window.clearTimeout(timer);
+  }, [toast, autoHideMs]);
+
+  return useMemo(() => ({ toast, showOk, showError, clear }), [toast, showOk, showError, clear]);
+}
+
+export function ToastProvider({ children, autoHideMs = 2600 }: { children: ReactNode; autoHideMs?: number }) {
+  const api = useToastState(autoHideMs);
+  return (
+    <ToastContext.Provider value={api}>
+      {children}
+      {api.toast ? <div className={`toast toast--${api.toast.type}`}>{api.toast.text}</div> : null}
+    </ToastContext.Provider>
+  );
+}
+
+export function useToast(): ToastApi {
+  const ctx = useContext(ToastContext);
+  if (!ctx) throw new Error("useToast must be used within ToastProvider");
+  return ctx;
+}