Clean up stale issue references in comments (gt-z5bri)

- daemon.go: Update gt-2hzl4 comment to past tense (timeout fallback is implemented)
- lifecycle.go: Remove "to be removed" promise for gt-psuw7 (code stays)
- keepalive_test.go: Remove tombstoned gt-gaxo epic reference
- doctor.go: Remove tombstoned gt-gaxo epic reference
- daemon_test.go: Remove tombstoned gt-gaxo epic reference

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/daemon/daemon.go

@@ -263,7 +263,7 @@ func (d *Daemon) ensureDeaconRunning() {
 	if beadErr == nil {
 		if beadState == "running" || beadState == "working" {
 			// Agent reports it's running - trust it
-			// Note: gt-2hzl4 will add timeout fallback for stale state
+			// Timeout fallback for stale state is in lifecycle.go
 			return
 		}
 	}

internal/daemon/daemon_test.go

@@ -207,7 +207,7 @@ func TestSaveLoadState_Roundtrip(t *testing.T) {
 }
 
 // NOTE: TestIsWitnessSession removed - isWitnessSession function was deleted
-// as part of ZFC cleanup (gt-gaxo). Witness poking is now Deacon's responsibility.
+// as part of ZFC cleanup. Witness poking is now Deacon's responsibility.
 
 func TestLifecycleAction_Constants(t *testing.T) {
 	// Verify constants have expected string values

internal/daemon/lifecycle.go

@@ -171,7 +171,7 @@ func (d *Daemon) executeLifecycleAction(request *LifecycleRequest) error {
 		}
 	}
 
-	// Check if session exists (legacy tmux detection - to be removed per gt-psuw7)
+	// Check if session exists (tmux detection still needed for lifecycle actions)
 	running, err := d.tmux.HasSession(sessionName)
 	if err != nil {
 		return fmt.Errorf("checking session: %w", err)