- Added tests for `ConvertOpenAIRequestToAntigravity` and `ConvertOpenAIRequestToGemini` to verify skipping of empty text parts while maintaining non-null structure. - Refactored part index logic to correctly handle placement of replay parts in `antigravity_reasoning_replay`. - Introduced helper functions `antigravityExistingReplayPartPath` and `antigravityReplayPartWritePath` for consistent replay part path management.