Add clipboard monitoring functionality to the agent. Implement clipboard event logging, including text and image capture, with support for retention policies. Update API to allow file deletion and enhance web interface for file management. Add tests for clipboard operations.

lib/clipmon/event.go

@@ -0,0 +1,10 @@
+package clipmon
+
+import "time"
+
+type Event struct {
+	Time time.Time
+	Kind string // "text" or "image"
+	Text string
+	ImagePath string // relative to clipboard dir, e.g. images/abc.png
+}