Stress testing for high-frequency data access

We need stress tests for high-volume data scenarios - especially heart rate and steps samples, which can generate thousands of records per day per user. What to test: **Database:** - Query performance with 1M+ samples for a single user (typical for several months of HR data at 1 sample/min) - Index efficiency on (user_id, timestamp) for range queries - Concurrent reads/writes - simulating multiple users syncing data simultaneously **Endpoints:** - GETs with various date ranges (day/week/month) - Response time when paginating through large datasets - Memory usage when serializing large responses ⚠️ Endpoint testing is blocked by this issue: https://github.com/the-momentum/open-wearables/issues/98