Refactor startup paths to use RuntimeConfig (gt-j0546)

Replaced all hardcoded 'claude --dangerously-skip-permissions' invocations
with configurable helpers from internal/config:

- GetRuntimeCommand(rigPath) - simple command string
- GetRuntimeCommandWithPrompt(rigPath, prompt) - with initial prompt
- BuildAgentStartupCommand(role, bdActor, rigPath, prompt) - generic agent
- BuildPolecatStartupCommand(rigName, polecatName, rigPath, prompt) - polecat
- BuildCrewStartupCommand(rigName, crewName, rigPath, prompt) - crew
- BuildStartupCommand(envVars, rigPath, prompt) - custom env vars

Files updated:
- internal/cmd/start.go (4 locations)
- internal/cmd/crew_lifecycle.go (2 locations)
- internal/cmd/crew_at.go (2 locations)
- internal/cmd/deacon.go
- internal/cmd/witness.go
- internal/cmd/up.go (2 locations)
- internal/cmd/handoff.go (2 locations)
- internal/daemon/daemon.go (3 locations)
- internal/daemon/lifecycle.go
- internal/session/manager.go
- internal/refinery/manager.go
- internal/boot/boot.go

This enables future support for alternative LLM runtimes (aider, etc.)
via rig/town settings configuration.

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

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

internal/cmd/up.go

@@ -262,11 +262,12 @@ func ensureSession(t *tmux.Tmux, sessionName, workDir, role string) error {
 	// Launch Claude
 	// Export GT_ROLE and BD_ACTOR in the command since tmux SetEnvironment only affects new panes
 	var claudeCmd string
+	runtimeCmd := config.GetRuntimeCommand("")
 	if role == "deacon" {
 		// Deacon uses respawn loop
-		claudeCmd = `export GT_ROLE=deacon BD_ACTOR=deacon GIT_AUTHOR_NAME=deacon && while true; do echo "⛪ Starting Deacon session..."; claude --dangerously-skip-permissions; echo ""; echo "Deacon exited. Restarting in 2s... (Ctrl-C to stop)"; sleep 2; done`
+		claudeCmd = `export GT_ROLE=deacon BD_ACTOR=deacon GIT_AUTHOR_NAME=deacon && while true; do echo "⛪ Starting Deacon session..."; ` + runtimeCmd + `; echo ""; echo "Deacon exited. Restarting in 2s... (Ctrl-C to stop)"; sleep 2; done`
 	} else {
-		claudeCmd = fmt.Sprintf(`export GT_ROLE=%s BD_ACTOR=%s GIT_AUTHOR_NAME=%s && claude --dangerously-skip-permissions`, role, role, role)
+		claudeCmd = config.BuildAgentStartupCommand(role, role, "", "")
 	}
 
 	if err := t.SendKeysDelayed(sessionName, claudeCmd, 200); err != nil {