Aurora SpotiRip desktop and web app

- Spotify playlist, library, album and artist browsing with in-app playback
- Song, playlist and album downloads via spotdl with YouTube and Bandcamp fallbacks
- Electron desktop app (castLabs Widevine) with a permanent sidebar layout
- Linux and Windows packaging scripts

helpers/directoryStore.tsx

@@ -0,0 +1,60 @@
+import type { WritableDirectoryHandle } from "./mp3Tags";
+
+const DB_NAME = "aurora-spotirip";
+const STORE_NAME = "handles";
+const OUTPUT_KEY = "output-directory";
+
+type PermissionedDirectoryHandle = WritableDirectoryHandle & {
+  queryPermission?: (options?: { mode?: "read" | "readwrite" }) => Promise<"granted" | "denied" | "prompt">;
+  requestPermission?: (options?: { mode?: "read" | "readwrite" }) => Promise<"granted" | "denied" | "prompt">;
+};
+
+function openDb() {
+  return new Promise<IDBDatabase>((resolve, reject) => {
+    const request = indexedDB.open(DB_NAME, 1);
+    request.onupgradeneeded = () => {
+      if (!request.result.objectStoreNames.contains(STORE_NAME)) {
+        request.result.createObjectStore(STORE_NAME);
+      }
+    };
+    request.onsuccess = () => resolve(request.result);
+    request.onerror = () => reject(request.error || new Error("Unable to open local folder settings."));
+  });
+}
+
+export async function saveOutputDirectory(handle: WritableDirectoryHandle) {
+  const db = await openDb();
+  try {
+    await new Promise<void>((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readwrite");
+      tx.objectStore(STORE_NAME).put(handle, OUTPUT_KEY);
+      tx.oncomplete = () => resolve();
+      tx.onerror = () => reject(tx.error || new Error("Unable to save output folder."));
+    });
+  } finally {
+    db.close();
+  }
+}
+
+export async function loadOutputDirectory(): Promise<WritableDirectoryHandle | undefined> {
+  if (typeof indexedDB === "undefined") return undefined;
+  const db = await openDb();
+  try {
+    return await new Promise<WritableDirectoryHandle | undefined>((resolve, reject) => {
+      const tx = db.transaction(STORE_NAME, "readonly");
+      const request = tx.objectStore(STORE_NAME).get(OUTPUT_KEY);
+      request.onsuccess = () => resolve(request.result as WritableDirectoryHandle | undefined);
+      request.onerror = () => reject(request.error || new Error("Unable to restore output folder."));
+    });
+  } finally {
+    db.close();
+  }
+}
+
+export async function ensureDirectoryWritePermission(handle: WritableDirectoryHandle) {
+  const permissioned = handle as PermissionedDirectoryHandle;
+  if (!permissioned.queryPermission || !permissioned.requestPermission) return true;
+  const current = await permissioned.queryPermission({ mode: "readwrite" });
+  if (current === "granted") return true;
+  return (await permissioned.requestPermission({ mode: "readwrite" })) === "granted";
+}