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 });
+  }
 }

src/core/io/KGProjectStorage.ts

@@ -206,10 +206,31 @@ export class KGProjectStorage {
     project.setName(newName);
     await this.save(newName, project, false);
 
+    // Copy media files from old to new location
+    await this.copyMediaFiles(oldName, newName);
+
     // Delete old location
     await this.delete(oldName);
   }
 
+  /**
+   * Save a project under a new name, migrating media files from the old folder.
+   * Used when the user renames the project and saves. Handles the case where the
+   * old folder doesn't exist yet (new project never saved).
+   */
+  public async saveWithRename(oldName: string, newName: string, data: KGProject): Promise<void> {
+    this.ensureInitialized();
+
+    // Save project JSON to the new folder
+    await this.save(newName, data, false);
+
+    // Migrate media files only if the old folder exists
+    if (await this.exists(oldName)) {
+      await this.copyMediaFiles(oldName, newName);
+      await this.delete(oldName);
+    }
+  }
+
   /**
    * Export a project folder as a zip Blob (.kgstudio bundle).
    * Includes project.json, meta.json, and all files in media/.
@@ -374,6 +395,42 @@ export class KGProjectStorage {
     return candidate;
   }
 
+  // --- Media migration ---
+
+  /**
+   * Copy all files from projects/<fromName>/media/ to projects/<toName>/media/.
+   * If the source media directory doesn't exist, returns without error.
+   */
+  private async copyMediaFiles(fromName: string, toName: string): Promise<void> {
+    try {
+      const fromDir = await this.projectsDirHandle!.getDirectoryHandle(fromName);
+      let fromMedia: FileSystemDirectoryHandle;
+      try {
+        fromMedia = await fromDir.getDirectoryHandle(OPFS_CONSTANTS.MEDIA_DIR);
+      } catch {
+        // No media directory in source — nothing to copy
+        return;
+      }
+
+      const toDir = await this.projectsDirHandle!.getDirectoryHandle(toName);
+      const toMedia = await toDir.getDirectoryHandle(OPFS_CONSTANTS.MEDIA_DIR, { create: true });
+
+      for await (const entry of fromMedia.values()) {
+        if (entry.kind === 'file') {
+          const fileHandle = entry as FileSystemFileHandle;
+          const file = await fileHandle.getFile();
+          const newHandle = await toMedia.getFileHandle(entry.name, { create: true });
+          const writable = await newHandle.createWritable();
+          await writable.write(await file.arrayBuffer());
+          await writable.close();
+        }
+      }
+    } catch (error) {
+      console.error(`Error copying media files from "${fromName}" to "${toName}":`, error);
+      throw error;
+    }
+  }
+
   // --- File I/O helpers ---
 
   private async writeFile(