feat: Update agent bead lookups to use correct tier (gt-eqptl)

Implement two-level beads architecture for agent lookups:

- Town-level agents (Mayor, Deacon) now use hq- prefix and are
  looked up in town beads (~/.beads/)
- Rig-level agents continue using rig prefix (e.g., gt-) and are
  looked up in rig beads

Changes:
- Add MayorBeadIDTown(), DeaconBeadIDTown(), DogBeadIDTown() helpers
- Add GetTownBeadsPath() for town beads path resolution
- Update gt status to pre-fetch town-level agent beads
- Update agentIDToBeadID() to use town-level IDs
- Update agent_beads_check.go to check/fix in correct tier
- Update agentAddressToIDs() in deacon.go

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

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

internal/beads/routes.go

@@ -130,6 +130,13 @@ func WriteRoutes(beadsDir string, routes []Route) error {
 	return nil
 }
 
+// GetTownBeadsPath returns the path to town-level beads directory.
+// Town beads store hq-* prefixed issues including Mayor, Deacon, and role beads.
+// The townRoot should be the Gas Town root directory (e.g., ~/gt).
+func GetTownBeadsPath(townRoot string) string {
+	return filepath.Join(townRoot, ".beads")
+}
+
 // GetPrefixForRig returns the beads prefix for a given rig name.
 // The prefix is returned without the trailing hyphen (e.g., "bd" not "bd-").
 // If the rig is not found in routes, returns "gt" as the default.