refactor: remove shell respawn loops from witness and deacon (gt-zxgu)

Shell loops bypassed the proper lifecycle architecture. Now:

- Witness: Launches Claude directly, daemon/deacon health-scan handles restart
- Deacon: Launches Claude directly, daemon detects exit and restarts
- Daemon: ensureDeaconRunning() now checks if Claude is running (pane cmd)
         and restarts it if session exists but Claude has exited
- gt deacon restart: Now does stop+start instead of Ctrl-C

This enforces proper lifecycle flow through LIFECYCLE mail and daemon
heartbeat rather than bypassing it with shell loops.

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

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

internal/cmd/witness.go

@@ -312,10 +312,10 @@ func ensureWitnessSession(rigName string, r *rig.Rig) (bool, error) {
 	theme := tmux.AssignTheme(rigName)
 	_ = t.ConfigureGasTownSession(sessionName, theme, rigName, "witness", "witness")
 
-	// Launch Claude in a respawn loop
+	// Launch Claude directly (no shell respawn loop)
+	// Restarts are handled by daemon via LIFECYCLE mail or deacon health-scan
 	// NOTE: No gt prime injection needed - SessionStart hook handles it automatically
-	loopCmd := `while true; do echo "👁️ Starting Witness for ` + rigName + `..."; claude --dangerously-skip-permissions; echo ""; echo "Witness exited. Restarting in 2s... (Ctrl-C to stop)"; sleep 2; done`
-	if err := t.SendKeysDelayed(sessionName, loopCmd, 200); err != nil {
+	if err := t.SendKeys(sessionName, "claude --dangerously-skip-permissions"); err != nil {
 		return false, fmt.Errorf("sending command: %w", err)
 	}