- Remove index_exists function that used op.get_bind() within transaction
- Use IF NOT EXISTS / IF EXISTS SQL syntax instead
- Fixes CREATE INDEX CONCURRENTLY error in Docker migration
- Add stream first byte timeout (TTFB) detection to trigger failover
when provider responds too slowly (configurable via STREAM_FIRST_BYTE_TIMEOUT)
- Add rate limit fail-open/fail-close strategy configuration
- Improve exception handling in stream prefetch with proper error classification
- Refactor UsageService with shared _prepare_usage_record method
- Add batch deletion for old usage records to avoid long transaction locks
- Update CLI adapters to use proper User-Agent headers for each CLI client
- Add composite indexes migration for usage table query optimization
- Fix streaming status display in frontend to show TTFB during streaming
- Remove sensitive JWT secret logging in auth service
