- Added Gemini thinking-loop detection helpers for near-duplicate and verbatim output checks.
- Wrapped `stream`, `streamPiNative`, and `streamSimple` dispatches with the loop guard.
- Emitted retryable empty-content loop errors and stopped completion events on loop hits.
- Added `enableGeminiThinkingLoopGuard` options for OpenAI compatibility with Gemini defaults and overrides.
