electron: external data dir, packaged path fix, footer responsive, test stabilization

- DB + uploads stored outside app bundle (survives updates)
- Router uses DOCUMENT_ROOT instead of __DIR__ (fixes AppImage paths)
- Footer count shifts right below 1250px, min-width 1150px
- Gallery opens gracefully on fetch errors
- Stabilized gallery, export, and find/replace tests with poll loops

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

electron/main.js

@@ -158,7 +158,7 @@ function createWindow() {
     mainWindow = new BrowserWindow({
         width: 1280,
         height: 820,
-        minWidth: 800,
+        minWidth: 1150,
         minHeight: 500,
         title: 'hyprcrd',
         backgroundColor: '#0f172a',