fix: resolve desktop entry launch failure and hide Electron menu bar on Linux

- Add --ozone-platform-hint=auto before app.whenReady() so Electron
  auto-detects X11 vs Wayland when launched from a desktop entry where
  the display protocol is not guaranteed (fixes immediate crash on
  Fedora/GNOME Wayland sessions)
- Add autoHideMenuBar: true to BrowserWindow so the default Chromium
  File/Edit/View/Help menu bar is hidden by default (still accessible
  via Alt); removes visible Electron significance from the packaged app
- Add scripts/rpm-after-install.sh and wire it via afterInstall in the
  electron-builder RPM config to chmod 4755 chrome-sandbox, ensuring
  the setuid sandbox works on kernels with restricted user namespaces

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/ui/package.json

@@ -275,7 +275,8 @@
         "libuuid"
       ],
       "compression": "xz",
-      "vendor": "AutoMaker Team"
+      "vendor": "AutoMaker Team",
+      "afterInstall": "scripts/rpm-after-install.sh"
     },
     "nsis": {
       "oneClick": false,