b0dc9df887
- Implemented `GetAPIKeyUsage` to expose recent request data grouped by provider and API key. - Added supporting function `mergeRecentRequestBuckets` for bucket aggregation. - Registered new endpoint `/v0/management/api-key-usage` in the management API. - Included extensive unit tests for provider and key-based grouping validation. - Updated `formatRecentRequestBucketLabel` to support configurable bucket duration.