Implement SyncWarden v0.1.0

Full Syncthing tray wrapper with:
- System tray with 5 icon states (idle/syncing/paused/error/disconnected)
- Syncthing REST API client with auto-discovered API key
- Long-polling event listener for real-time status
- Transfer rate monitoring, folder tracking, recent files, conflict counting
- Full context menu with folders, recent files, settings toggles
- Embedded admin panel binary (webview, requires CGO)
- OS notifications via beeep (per-event configurable)
- Syncthing process management with auto-restart
- Cross-platform installer with autostart
- CI pipeline for Linux (.deb + .tar.gz) and Windows (.zip)

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

packaging/nfpm.yaml

@@ -0,0 +1,27 @@
+name: syncwarden
+arch: amd64
+platform: linux
+version: "${VERSION}"
+maintainer: "calic"
+description: "Lightweight system tray wrapper for Syncthing"
+vendor: "calic"
+homepage: "https://git.davoryn.de/calic/syncwarden"
+license: MIT
+
+contents:
+  - src: ./syncwarden
+    dst: /usr/bin/syncwarden
+  - src: ./syncwarden-panel
+    dst: /usr/bin/syncwarden-panel
+  - src: ./packaging/linux/syncwarden.desktop
+    dst: /etc/xdg/autostart/syncwarden.desktop
+    type: config
+
+scripts:
+  postinstall: ./packaging/linux/postinstall.sh
+  preremove: ./packaging/linux/preremove.sh
+
+depends:
+  - syncthing
+recommends:
+  - libwebkit2gtk-4.0-37