refactor: migrate callers from deprecated MayorBeadID/DeaconBeadID to Town variants (gt-gbw0a)

Update all callers of deprecated MayorBeadID()/DeaconBeadID() to use
MayorBeadIDTown()/DeaconBeadIDTown() which return hq- prefix IDs for
town-level beads storage.

Changes:
- internal/daemon/lifecycle.go: identityToAgentBeadID and checkStaleAgents
- internal/cmd/prime.go: getAgentBeadID
- internal/cmd/molecule_status.go: buildAgentBeadID
- internal/cmd/prime_test.go: update expected values to hq-*
- Comments updated to reflect hq- prefix for town-level agents

The deprecated functions remain for backward compatibility and are used
by the migration tool (migrate_agents.go).

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

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

internal/daemon/lifecycle.go

@@ -715,9 +715,9 @@ func (d *Daemon) identityToAgentBeadID(identity string) string {
 
 	switch parsed.RoleType {
 	case "deacon":
-		return beads.DeaconBeadID()
+		return beads.DeaconBeadIDTown()
 	case "mayor":
-		return beads.MayorBeadID()
+		return beads.MayorBeadIDTown()
 	case "witness":
 		return beads.WitnessBeadID(parsed.RigName)
 	case "refinery":
@@ -741,8 +741,8 @@ const DeadAgentTimeout = 15 * time.Minute
 func (d *Daemon) checkStaleAgents() {
 	// Known agent bead IDs to check
 	agentBeadIDs := []string{
-		beads.DeaconBeadID(),
-		beads.MayorBeadID(),
+		beads.DeaconBeadIDTown(),
+		beads.MayorBeadIDTown(),
 	}
 
 	// Dynamically discover rigs from the rigs config