Maintenance-mode criteria (future)

Do not declare maintenance-only until:

• at least one stable public release cycle (v0.1.x → v0.2.x) with migration experience.
• documented external adopters and integrations.
• no pending contract changes or experimental ND features.
• governance decision recorded in design_diary and freeze_criteria.

Until then: bijux-vex is contract-complete and open to empirical refinement.