fix: Use StatusHooked instead of StatusPinned for hook queries

The hook mechanism was broken because gt hook sets status=hooked
but gt mol status was querying for status=pinned.

Adds StatusHooked constant and updates queries accordingly.

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

internal/beads/handoff.go

@@ -7,8 +7,13 @@ import (
 )
 
 // StatusPinned is the status for pinned beads that never get closed.
+// These are "domain table" beads like role definitions that persist permanently.
 const StatusPinned = "pinned"
 
+// StatusHooked is the status for beads on an agent's hook (work assignment).
+// This is distinct from pinned - hooked beads are active work, not permanent records.
+const StatusHooked = "hooked"
+
 // HandoffBeadTitle returns the well-known title for a role's handoff bead.
 func HandoffBeadTitle(role string) string {
 	return role + " Handoff"