fix(install): add gt:role label to role beads during creation (#383)

Role beads created by gt install were missing the gt:role label required
by GetRoleConfig(), causing witness startup to fail with:
"bead hq-witness-role is not a role bead (missing gt:role label)"

This regression was introduced in 96970071 which migrated from type-based
to label-based bead classification. The install code used raw exec.Command
instead of the beads API, so it wasn't updated to add labels.

Changes:
- Use bd.CreateWithID() API which auto-converts Type:"role" to gt:role label
- Add RoleLabelCheck doctor migration to fix existing installations
- Add comprehensive unit tests with mocked dependencies

Co-authored-by: julianknutsen <julianknutsen@users.noreply.github>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

internal/cmd/doctor.go

@@ -126,6 +126,7 @@ func runDoctor(cmd *cobra.Command, args []string) error {
 	d.Register(doctor.NewBootHealthCheck())
 	d.Register(doctor.NewBeadsDatabaseCheck())
 	d.Register(doctor.NewCustomTypesCheck())
+	d.Register(doctor.NewRoleLabelCheck())
 	d.Register(doctor.NewFormulaCheck())
 	d.Register(doctor.NewBdDaemonCheck())
 	d.Register(doctor.NewPrefixConflictCheck())

internal/cmd/install.go

@@ -492,18 +492,18 @@ func initTownAgentBeads(townPath string) error {
 			continue // Already exists
 		}
 
-		// Create role bead using bd create --type=role
-		cmd := exec.Command("bd", "create",
-			"--type=role",
-			"--id="+role.id,
-			"--title="+role.title,
-			"--description="+role.desc,
-		)
-		cmd.Dir = townPath
-		if output, err := cmd.CombinedOutput(); err != nil {
+		// Create role bead using the beads API
+		// CreateWithID with Type: "role" automatically adds gt:role label
+		_, err := bd.CreateWithID(role.id, beads.CreateOptions{
+			Title:       role.title,
+			Type:        "role",
+			Description: role.desc,
+			Priority:    -1, // No priority
+		})
+		if err != nil {
 			// Log but continue - role beads are optional
-			fmt.Printf("   %s Could not create role bead %s: %s\n",
-				style.Dim.Render("⚠"), role.id, strings.TrimSpace(string(output)))
+			fmt.Printf("   %s Could not create role bead %s: %v\n",
+				style.Dim.Render("⚠"), role.id, err)
 			continue
 		}
 		fmt.Printf("   ✓ Created role bead: %s\n", role.id)