fix: Electron download via native save dialog

- Add file:saveRendered IPC handler in main process
- Copies rendered file from internal renders dir to user-chosen path
- Update preload with saveRenderedFile bridge method
- Update useExportQueue downloadJob: detect Electron → native save dialog
- Web mode fallback preserved (<a> tag download)

src/electron/main.ts

@@ -201,6 +201,55 @@ function setupIPC() {
     userData: app.getPath('userData'),
     isPackaged: app.isPackaged,
   }));
+
+  // Save rendered file to user-chosen location
+  ipcMain.handle('file:saveRendered', async (_event, renderUrl: string, defaultName: string) => {
+    if (!mainWindow) return null;
+
+    // Extract the filename from the URL (e.g. /api/renders/abc123.mp4 → abc123.mp4)
+    const filename = renderUrl.split('/').pop();
+    if (!filename) return null;
+
+    // Determine the source file path in RENDERS_DIR
+    const rendersDir = process.env.BRADLY_RENDERS_DIR
+      || path.join(process.cwd(), 'renders');
+    const sourcePath = path.join(rendersDir, filename);
+
+    // Verify the source file exists
+    if (!fs.existsSync(sourcePath)) {
+      console.error('❌ Rendered file not found:', sourcePath);
+      return null;
+    }
+
+    // Determine file extension and filters
+    const ext = path.extname(filename).slice(1); // 'mp4', 'png', etc.
+    const filterMap: Record<string, { name: string; extensions: string[] }[]> = {
+      mp4: [{ name: 'Video MP4', extensions: ['mp4'] }],
+      webm: [{ name: 'Video WebM', extensions: ['webm'] }],
+      gif: [{ name: 'GIF', extensions: ['gif'] }],
+      png: [{ name: 'Imagen PNG', extensions: ['png'] }],
+      jpeg: [{ name: 'Imagen JPEG', extensions: ['jpeg', 'jpg'] }],
+    };
+
+    // Show native save dialog
+    const result = await dialog.showSaveDialog(mainWindow, {
+      title: 'Guardar exportación',
+      defaultPath: path.join(app.getPath('downloads'), defaultName),
+      filters: filterMap[ext] || [{ name: 'Archivo', extensions: [ext] }],
+    });
+
+    if (result.canceled || !result.filePath) return null;
+
+    // Copy the rendered file to the chosen location
+    try {
+      await fs.promises.copyFile(sourcePath, result.filePath);
+      console.log(`✅ Saved to: ${result.filePath}`);
+      return result.filePath;
+    } catch (err) {
+      console.error('❌ Failed to save file:', err);
+      return null;
+    }
+  });
 }
 
 // ═══ Remotion Browser Pre-download ═══

src/electron/preload.ts

@@ -24,6 +24,19 @@ const electronAPI = {
   showOpenDialog: (options: Electron.OpenDialogOptions) =>
     ipcRenderer.invoke('dialog:open', options) as Promise<Electron.OpenDialogReturnValue>,
 
+  // ─── File Operations ───
+
+  /**
+   * Save a rendered file to a user-chosen location.
+   * Shows a native save dialog, then copies the rendered file to the chosen path.
+   * 
+   * @param renderUrl - The relative URL of the rendered file (e.g. /api/renders/abc.mp4)
+   * @param defaultName - Suggested filename for the save dialog
+   * @returns The saved file path, or null if cancelled
+   */
+  saveRenderedFile: (renderUrl: string, defaultName: string) =>
+    ipcRenderer.invoke('file:saveRendered', renderUrl, defaultName) as Promise<string | null>,
+
   // ─── App Info ───
   getAppInfo: () =>
     ipcRenderer.invoke('app:info') as Promise<{

src/hooks/useExportQueue.ts

@@ -176,12 +176,29 @@ export function useExportQueue() {
   }, []);
 
   // ─── Download ───
-  const downloadJob = useCallback((job: RenderJobClient) => {
+  const downloadJob = useCallback(async (job: RenderJobClient) => {
     if (!job.downloadUrl) return;
 
+    const defaultName = `export-${job.id.slice(0, 8)}.${job.format}`;
+
+    // In Electron, use native save dialog via IPC
+    const electronAPI = (window as any).electronAPI;
+    if (electronAPI?.saveRenderedFile) {
+      try {
+        const savedPath = await electronAPI.saveRenderedFile(job.downloadUrl, defaultName);
+        if (savedPath) {
+          console.log('✅ Saved to:', savedPath);
+        }
+      } catch (err) {
+        console.error('Save failed:', err);
+      }
+      return;
+    }
+
+    // Web fallback: <a> tag download
     const a = document.createElement('a');
     a.href = job.downloadUrl;
-    a.download = `export-${job.id.slice(0, 8)}.${job.format}`;
+    a.download = defaultName;
     document.body.appendChild(a);
     a.click();
     document.body.removeChild(a);