fix(loop): close events channel when loop finishes

The events channel was never closed after Run() returned, causing the
Manager's event forwarding goroutine to block indefinitely. This led to
the TUI becoming unresponsive after a ralph loop completed.

Author: MiniCodeMonkey

internal/loop/loop.go

@@ -91,6 +91,7 @@ func (l *Loop) Run(ctx context.Context) error {
 		return fmt.Errorf("failed to open log file: %w", err)
 	}
 	defer l.logFile.Close()
+	defer close(l.events)
 
 	for {
 		l.mu.Lock()