- Added `GetGJSONBytesNoCopy` in `internal/util` for safe, no-copy JSON parse operations leveraging `unsafe`.
- Replaced `gjson.GetBytes` with the new helper in key payload processing paths (`kimi_executor`, `vertex_payload_helpers`, etc.) to improve performance.
- Added unit tests for behavior validation, including edge cases with empty input.
- Introduced `SetStringIfDifferent`, `SetBoolIfDifferent`, and similar helpers in `payload_helpers` to avoid unnecessary writes during JSON modifications.
- Simplified message patching in `kimi_executor` for reasoning and tool call adjustments.
- Updated all executors (Gemini, Codex, XAI, Antigravity, etc.) to use the new helpers, enhancing readability and potentially reducing overhead.
- Removed obsolete `filterKimiEmptyAssistantMessages` function in `kimi_executor`.