fix(sling): auto-apply mol-polecat-work (#288) and fix wisp orphan lifecycle bug (#842) (#859)

fix(sling): auto-apply mol-polecat-work (#288) and fix wisp orphan lifecycle bug (#842)

Fixes the formula-on-bead pattern to hook the base bead instead of the wisp:
- Auto-apply mol-polecat-work when slinging bare beads to polecats
- Hook BASE bead with attached_molecule pointing to wisp  
- gt done now closes attached molecule before closing hooked bead
- Convoys complete properly when work finishes

Fixes #288, #842, #858

internal/beads/handoff.go

@@ -158,12 +158,9 @@ func (b *Beads) AttachMolecule(pinnedBeadID, moleculeID string) (*Issue, error)
 		return nil, fmt.Errorf("fetching pinned bead: %w", err)
 	}
 
-	// Allow pinned beads OR open polecat agent beads (polecats have a lifecycle, not permanent)
+	// Only allow pinned beads (permanent records like role definitions)
 	if issue.Status != StatusPinned {
-		_, role, _, ok := ParseAgentBeadID(pinnedBeadID)
-		if !(issue.Status == "open" && ok && role == "polecat") {
-			return nil, fmt.Errorf("issue %s is not pinned or open polecat (status: %s)", pinnedBeadID, issue.Status)
-		}
+		return nil, fmt.Errorf("issue %s is not pinned (status: %s)", pinnedBeadID, issue.Status)
 	}
 
 	// Build attachment fields with current timestamp