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>

cmd/panel/main.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"flag"
+	"log"
+
+	"github.com/webview/webview_go"
+)
+
+func main() {
+	addr := flag.String("addr", "http://localhost:8384", "Syncthing address")
+	flag.Parse()
+
+	w := webview.New(false)
+	if w == nil {
+		log.Fatal("failed to create webview")
+	}
+	defer w.Destroy()
+
+	w.SetTitle("SyncWarden — Admin Panel")
+	w.SetSize(1024, 768, webview.HintNone)
+	w.Navigate(*addr)
+	w.Run()
+}