fix(doctor): add role beads check with shared definitions (#378)

Role beads (hq-*-role) are templates that define role characteristics.
They are created during gt install but creation may fail silently.
Without role beads, agents fall back to defaults.

Changes:
- Add beads.AllRoleBeadDefs() as single source of truth for role bead definitions
- Update gt install to use shared definitions
- Add doctor check that detects missing role beads (warning, not error)
- Doctor --fix creates missing role beads

Fixes #371

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

internal/cmd/doctor.go

@@ -153,6 +153,7 @@ func runDoctor(cmd *cobra.Command, args []string) error {
 	d.Register(doctor.NewPatrolRolesHavePromptsCheck())
 	d.Register(doctor.NewAgentBeadsCheck())
 	d.Register(doctor.NewRigBeadsCheck())
+	d.Register(doctor.NewRoleBeadsCheck())
 
 	// NOTE: StaleAttachmentsCheck removed - staleness detection belongs in Deacon molecule