V2-S5: Safety Recommendations + cross-module initiation

- Add safety_recommendations table (reference, statement, rationale, priority,
  department, manager, response enum accepted/partially_accepted/rejected/deferred,
  justification, due date, status)
- Add SafetyRecommendation model
- Add RecommendationService: create (generates SR-YYYY-00000 reference), respond
  (validates response + mandatory justification), audited
- Add SafetyRecommendationController: index, store (from risk assessment), respond
- Add Recommendations/Index React page + SafetyRecommendation TS type
- Add routes: recommendations.index, recommendations.store (risk.edit),
  recommendations.respond (risk.approve)
- Add 3 Pest tests: issue recommendation with reference, response justification
  validation, index access
- Cross-module initiation: risk assessment create accepts source_type/source_id
  for Golden Thread provenance (carried from V2-S2 conduct risk assessment)
