BE13 – Wearable Device Data Integration

[TienNguyen3711]

Summary
This PR adds backend support for wearable device data ingestion and refactors database access into repositories to improve maintainability and future extensibility.

Changes
Added wearable data endpoints, validation, normalization, storage flow, and tests for supported metrics such as steps, heart rate, sleep duration, and calories burned.
Also separated direct database access from services by introducing repository files under repositories/wearable-device/ and updating related services to use them.

Test
Ran:

npx mocha test/recommendationService.test.js test/wearableDataService.test.js test/wearableDataController.test.js test/wearableDataValidator.test.js

Result: 16 passing

[Vedant1515]

Kindly fix the merge conflicts.

[TienNguyen3711]

Kindly fix the merge conflicts.

The BE12 and B13 branches contain features developed after Sprint 2. Therefore, additional conflicts may arise if they are not merged immediately. I will revise everything before the end of Sprint 2 to ensure there are no more conflicts.