progress indicator added

lib/progress.ts

@@ -0,0 +1,16 @@
+export type GenerateProgressEvent =
+  | { phase: "generate"; current: number; total: number }
+  | { phase: "zip"; current: number; total: number }
+  | { phase: "done"; id: string }
+  | { phase: "error"; message: string };
+
+export function isProgressEvent(value: unknown): value is GenerateProgressEvent {
+  if (!value || typeof value !== "object") return false;
+  const phase = (value as { phase?: unknown }).phase;
+  return (
+    phase === "generate" ||
+    phase === "zip" ||
+    phase === "done" ||
+    phase === "error"
+  );
+}