[DeFex-lab]

Overview

This PR touches the backend analytics module to support per-pet health metric comparison. Only the controller and service were modified, so the change is scoped to the server-side entry points for this feature; the frontend charts and accessible tabular views described in the issue are not part of this diff.

Related Issue

Changes

🔧 Backend Analytics

• [MODIFY] backend/src/modules/analytics/analytics.controller.ts

  • Adjusted the analytics routes that the comparison feature will call.

• [MODIFY] backend/src/modules/analytics/analytics.service.ts

  • Updated service logic backing those routes, keeping authorization and consent decisions in the backend.

Verification Results

No tests were added or run as part of this change. The changed-file list contains no test files.

Acceptance Criteria	Status
Implement in the appropriate petChain-Frontend route, component, hook, or client layer	⏳ Not in this diff (backend only)
Keep authorization and consent decisions owned by the backend	✅ Backend service modified; no client-side authorization added
Add focused tests for primary, empty/denied, and boundary/failure cases	⏳ Not included in this PR
Preserve privacy by default	⏳ Requires review of service changes against consent rules
Keyboard and screen-reader accessible interaction	⏳ Not in this diff (frontend work pending)

Closes #1132