feat(admin-web): add web/admin to repo

Initial commit of the Super-Admin web panel (Next.js + TypeScript).
CI admin-web-check job was failing because the directory was never
tracked in git.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/admin/src/lib/notify.ts

@@ -0,0 +1,56 @@
+import { toast } from "sonner";
+import { ApiClientError } from "@/lib/api/client";
+
+export type NotifyOptions = {
+  description?: string;
+  duration?: number;
+};
+
+function baseOptions(opts?: NotifyOptions) {
+  return {
+    description: opts?.description,
+    duration: opts?.duration ?? 4000,
+  };
+}
+
+/** Toast notifications — use for transient success/error/info across the app */
+export const notify = {
+  success(message: string, opts?: NotifyOptions) {
+    toast.success(message, baseOptions(opts));
+  },
+  error(message: string, opts?: NotifyOptions) {
+    toast.error(message, { ...baseOptions(opts), duration: opts?.duration ?? 5500 });
+  },
+  warning(message: string, opts?: NotifyOptions) {
+    toast.warning(message, baseOptions(opts));
+  },
+  info(message: string, opts?: NotifyOptions) {
+    toast.info(message, baseOptions(opts));
+  },
+  loading(message: string) {
+    return toast.loading(message);
+  },
+  dismiss(id?: string | number) {
+    toast.dismiss(id);
+  },
+  promise<T>(
+    promise: Promise<T>,
+    messages: { loading: string; success: string; error?: string }
+  ) {
+    return toast.promise(promise, {
+      loading: messages.loading,
+      success: messages.success,
+      error: messages.error ?? messages.loading,
+    });
+  },
+};
+
+export function getErrorMessage(err: unknown, fallback: string): string {
+  if (err instanceof ApiClientError) return err.message;
+  if (err instanceof Error && err.message) return err.message;
+  return fallback;
+}
+
+export function notifyError(err: unknown, fallback: string) {
+  notify.error(getErrorMessage(err, fallback));
+}