Add wisp-gc doctor check, integrate into gt doctor --fix (gt-psj76.2)

- Implement WispGCCheck in internal/doctor/wisp_check.go
  - Scans rigs for wisps older than 1 hour threshold
  - Fix runs `bd --no-daemon wisp gc` in each affected rig
- Register wisp-gc check in gt doctor
- Update help text to document cleanup checks
- Simplify Deacon patrol session-gc step to just use gt doctor --fix

Now `gt doctor --fix` handles all cleanup:
- orphan-sessions: Kill orphaned tmux sessions
- orphan-processes: Kill orphaned Claude processes
- wisp-gc: Garbage collect abandoned wisps (>1h)

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

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

internal/cmd/doctor.go

@@ -24,6 +24,11 @@ var doctorCmd = &cobra.Command{
 Doctor checks for common configuration issues, missing files,
 and other problems that could affect workspace operation.
 
+Cleanup checks (fixable):
+  - orphan-sessions          Detect orphaned tmux sessions
+  - orphan-processes         Detect orphaned Claude processes
+  - wisp-gc                  Detect and clean abandoned wisps (>1h)
+
 Patrol checks:
   - patrol-molecules-exist   Verify patrol molecules exist
   - patrol-hooks-wired       Verify daemon triggers patrols
@@ -66,6 +71,7 @@ func runDoctor(cmd *cobra.Command, args []string) error {
 	d.Register(doctor.NewBeadsDatabaseCheck())
 	d.Register(doctor.NewOrphanSessionCheck())
 	d.Register(doctor.NewOrphanProcessCheck())
+	d.Register(doctor.NewWispGCCheck())
 	d.Register(doctor.NewBranchCheck())
 	d.Register(doctor.NewBeadsSyncOrphanCheck())
 	d.Register(doctor.NewIdentityCollisionCheck())