fix(ui): harden main window interactions

src/store/downloadProgressStore.ts

@@ -0,0 +1,26 @@
+import { create } from 'zustand';
+import type { DownloadProgressEvent } from '../bindings/DownloadProgressEvent';
+
+interface DownloadProgressState {
+  progressMap: Record<string, DownloadProgressEvent>;
+  updateDownloadProgress: (id: string, payload: DownloadProgressEvent) => void;
+  clearDownloadProgress: (id: string) => void;
+}
+
+export const useDownloadProgressStore = create<DownloadProgressState>((set) => ({
+  progressMap: {},
+  updateDownloadProgress: (id, payload) =>
+    set((state) => ({
+      progressMap: {
+        ...state.progressMap,
+        [id]: payload,
+      },
+    })),
+  clearDownloadProgress: (id) =>
+    set((state) => {
+      if (!(id in state.progressMap)) return state;
+      const next = { ...state.progressMap };
+      delete next[id];
+      return { progressMap: next };
+    }),
+}));