feat: native clipboard image sync (Linux, opt-in sync_images)

internal/config/config.go

@@ -35,6 +35,7 @@ type DaemonConfig struct {
 	HistorySize    int    `toml:"history_size"`
 	Discovery      bool   `toml:"discovery"`
 	Notify         bool   `toml:"notify"`
+	SyncImages     bool   `toml:"sync_images"`
 	ReceiveFiles   bool   `toml:"receive_files"`
 	ReceiveDir     string `toml:"receive_dir"`
 }