feat(install): Add hq-dog-role to initTownAgentBeads (gt-2jjry)

Add Dog role bead creation to the roleDefs slice, ensuring Dog
agents have their role definition created during gt install.

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

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

internal/cmd/install.go

@@ -388,6 +388,11 @@ func initTownAgentBeads(townPath string) error {
 			title: "Deacon Role",
 			desc:  "Role definition for Deacon agents. Daemon beacon for heartbeats and monitoring.",
 		},
+		{
+			id:    beads.DogRoleBeadIDTown(),
+			title: "Dog Role",
+			desc:  "Role definition for Dog agents. Town-level workers for cross-rig tasks.",
+		},
 		{
 			id:    beads.WitnessRoleBeadIDTown(),
 			title: "Witness Role",