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>

internal/tray/icons.go

@@ -0,0 +1,20 @@
+package tray
+
+import (
+	"log"
+
+	"github.com/energye/systray"
+
+	"git.davoryn.de/calic/syncwarden/internal/icons"
+	"git.davoryn.de/calic/syncwarden/internal/monitor"
+)
+
+// updateIcon renders and sets the tray icon based on status.
+func updateIcon(status monitor.AggregateStatus) {
+	iconData, err := icons.Render(status.State)
+	if err != nil {
+		log.Printf("icon render error: %v", err)
+		return
+	}
+	systray.SetIcon(iconData)
+}