refactor: update lifecycle mail targets from daemon/ to deacon/ (gt-5af.5)

Update all code and documentation to use deacon/ instead of daemon/
for lifecycle mail targets:

- internal/cmd/handoff.go: getManager() returns deacon/ for Mayor/Witness
- internal/daemon/lifecycle.go: ProcessLifecycleRequests uses deacon/ inbox
- docs/architecture.md: update all references in lifecycle docs
- scripts/mayor-respawn-daemon.sh: use BD_IDENTITY=deacon for mail commands

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

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

internal/cmd/handoff.go

@@ -225,7 +225,7 @@ func preFlightChecks() error {
 func getManager(role Role) string {
 	switch role {
 	case RoleMayor, RoleWitness:
-		return "daemon/"
+		return "deacon/"
 	case RolePolecat, RoleRefinery:
 		// Would need rig context to determine witness address
 		// For now, use a placeholder pattern
@@ -233,7 +233,7 @@ func getManager(role Role) string {
 	case RoleCrew:
 		return "human" // Crew is human-managed
 	default:
-		return "daemon/"
+		return "deacon/"
 	}
 }