fix: missing media files when renaming + saving the project

src/core/io/KGAudioFileStorage.ts

@@ -7,13 +7,14 @@ import { OPFS_CONSTANTS } from '../../constants/coreConstants';
 export class KGAudioFileStorage {
   /**
    * Store an audio file in the project's media/ directory.
+   * Creates the project and media directories if they don't exist yet.
    */
   public static async storeAudioFile(
     projectName: string,
     fileId: string,
     file: File
   ): Promise<void> {
-    const mediaDir = await KGAudioFileStorage.getMediaDir(projectName);
+    const mediaDir = await KGAudioFileStorage.getOrCreateMediaDir(projectName);
     const fileHandle = await mediaDir.getFileHandle(fileId, { create: true });
     const writable = await fileHandle.createWritable();
     await writable.write(await file.arrayBuffer());
@@ -61,7 +62,8 @@ export class KGAudioFileStorage {
   }
 
   /**
-   * Get the media directory handle for a project.
+   * Get the media directory handle for an existing project (read/delete path).
+   * Does NOT create directories — fails if project folder doesn't exist.
    */
   private static async getMediaDir(projectName: string): Promise<FileSystemDirectoryHandle> {
     const root = await navigator.storage.getDirectory();
@@ -69,4 +71,15 @@ export class KGAudioFileStorage {
     const projectDir = await projectsDir.getDirectoryHandle(projectName);
     return projectDir.getDirectoryHandle(OPFS_CONSTANTS.MEDIA_DIR, { create: true });
   }
+
+  /**
+   * Get or create the media directory handle for a project (write path).
+   * Creates project and media directories if they don't exist.
+   */
+  private static async getOrCreateMediaDir(projectName: string): Promise<FileSystemDirectoryHandle> {
+    const root = await navigator.storage.getDirectory();
+    const projectsDir = await root.getDirectoryHandle(OPFS_CONSTANTS.ROOT_DIR, { create: true });
+    const projectDir = await projectsDir.getDirectoryHandle(projectName, { create: true });
+    return projectDir.getDirectoryHandle(OPFS_CONSTANTS.MEDIA_DIR, { create: true });
+  }
 }