Implement automated deletion of expired reservation requests per data retention policy

[Copilot]

Per SRD/BRD data retention policy, CLOSED reservation requests must be deleted after 6 months. This implements automated cleanup via daily Azure Functions timer trigger.

Changes

Cellix Framework Extension

• Added registerAzureFunctionTimerHandler() to support timer triggers alongside HTTP handlers
• Modified handler registration to dispatch based on handler type (http | timer)

Domain & Persistence

• Added ReservationRequest.requestDelete() with canDeleteRequest permission (system passport only)
• Added ReservationRequestReadRepository.getExpiredClosed() query: state='Closed' AND updatedAt < (now - 182.5 days)
• Date arithmetic uses milliseconds to avoid month boundary edge cases

Application Service

• Created deleteExpiredReservationRequests() with OpenTelemetry tracing
• Batch processes expired requests with per-item error isolation
• Metrics: reservation_requests.expired.count, reservation_requests.deleted.count

Timer Trigger

• Registered daily cleanup job (2 AM UTC, NCRONTAB: 0 0 2 * * *)
• Uses system passport via forRequest() without auth header

// Example: Timer handler registration in apps/api/src/index.ts
.registerAzureFunctionTimerHandler(
  'cleanup-expired-reservation-requests',
  { schedule: '0 0 2 * * *', runOnStartup: false },
  cleanupExpiredReservationRequestsHandlerCreator,
)

Testing

• Unit tests for deletion service (mocked data sources, error handling, edge cases)
• BDD scenario for getExpiredClosed() repository query
• Comprehensive documentation in apps/docs/docs/data-retention-reservation-requests.md

Notes

Follows same pattern as issue #199 (Listing deletion). System passport grants deletion permission for automated cleanup only.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Reservation Request - Expired Deletion</issue_title>
<issue_description>## Background
Reservation Requests that have reached the expired state (completed and archived for 6 months) must be deleted from the operational database (Azure Cosmos DB, MongoDB API) per the system's data retention policy. This ensures compliance with storage limits and keeps the database clean of stale records.

Task Description

• Implement logic to automatically delete Reservation Requests from the operational database once they are marked as expired and the 6-month archival window has elapsed.
• Ensure this process runs on a schedule or is triggered reliably to avoid retention policy violations.
• Log deletion events for observability and auditing (OpenTelemetry/Azure Monitor integration).
• Confirm that all related data (messages, notifications, etc.) are also cleaned up if required by retention rules.
• Update documentation to clarify data retention behavior for Reservation Requests.

Acceptance Criteria

• Reservation Requests in the expired state are deleted after 6 months.
• Deletion is observable via logs and metrics.
• No residual data remains in the database for deleted requests.
• Documentation is updated to reflect retention and deletion logic.

References

• See BRD/SRD: Data Retention Strategy
• ADR: OpenTelemetry, Observability
• Azure Cosmos DB (MongoDB API) deletion requirements
• documents/share-thrift-srd-bronze.md
• documents/share-thrift-brd.md
  </issue_description>

<agent_instructions>Use the design and decisions discussed in issue #199 (#199) as context for this task. Ensure the solution follows those guidelines.
</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Reservation Request - Expired Deletion #202

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