feat: integrate Electron for desktop application support

- Added Electron entry point in `electron/main.js` to run the Express server in-process and open the main application window.
- Updated `package.json` to include Electron dependencies and scripts for building and running the application.
- Refactored server startup logic into `server/start.js` for better modularity and to support both CLI and Electron usage.
- Implemented environment variable handling for database and image paths to accommodate Electron's packaging.
- Created a script `server/scripts/promote-morphix.js` to merge admin and morphix accounts into a single user.
- Adjusted image root path resolution in `server/media/images.js` to allow for environment variable overrides.
- Cleaned up `server/index.js` to delegate server initialization to the new `startServer` function.

server/media/images.js

@@ -11,7 +11,11 @@ import { fileURLToPath } from 'node:url';
 import { getDb } from '../db/index.js';
 
 const __dirname = dirname(fileURLToPath(import.meta.url));
-const ROOT = resolve(__dirname, '..', '..', 'data', 'images');
+// Where cover art lives. Overridable via env so Electron (packaged) can point
+// it at app.getPath('userData')/data/images instead of the read-only asar dir.
+const ROOT = process.env.ORADIO_IMAGE_ROOT
+    ? resolve(process.env.ORADIO_IMAGE_ROOT)
+    : resolve(__dirname, '..', '..', 'data', 'images');
 const STATIONS_DIR = join(ROOT, 'stations');
 // A browser-like UA is required by Wikimedia and several CDNs; an opaque
 // UA like "OnlineRadioExplorer/0.1" gets HTTP 400/403 from upload.wikimedia.org.