Context

Follow-up from #1113 (versioning infrastructure evaluation). Role definitions control authority scope, budget limits, and skill requirements. Versioning enables audit trails for authorization decisions.

Value Assessment

• Versioning value: 7/10 (HIGH)
• Audit trail: Track changes to authority scope, budget limits, model tier recommendations
• Rollback value: HIGH -- restore prior authorization scope
• Reproducibility: Task approval decisions can reference role version at decision time
• Change frequency: Low (quarterly)

Design Decision Needed

• Option A: VersionSnapshot[Role] -- per-role versioning (granular, more rows)
• Option B: VersionSnapshot[RoleCatalog] -- org-wide catalog snapshot (simpler, fewer rows, but stores entire catalog per change)

Recommend Option A for granularity, but needs discussion.

Implementation

1. Design decision on granularity
2. Create role version table via SQLiteVersionRepository[T]
3. Wire into persistence backend
4. Audit API: list role versions with change summary

Depends on #1131 and #1132.