gt hook status failed with "cannot determine agent identity (role: unknown)"
when run from rig root directories like ~/gt/beads. The cwd-based detection
only recognizes specific agent directories (witness/, polecats/foo/, etc.)
but not rig roots.
Now falls back to GT_ROLE env var when detectRole returns unknown, matching
the pattern used by GetRoleWithContext and other role detection code.
Fixes gt-6pg
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
809b0eb028