Add drift state, persistence, and override controls to controller

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

internal/store/store.go

@@ -19,6 +19,8 @@ type Snapshot struct {
 	DeadlineUnixSecs int64               `json:"deadline_unix_secs,omitempty"`
 	SessionID        string              `json:"session_id,omitempty"`
 	OutcomePending   string              `json:"outcome_pending,omitempty"`
+
+	AllowedWindowClasses []string `json:"allowed_window_classes,omitempty"`
 }
 
 // DefaultPath returns ~/.antidrift/state.json.