- Register static model definitions for devin/gemini-3-8-flash (1M context, Google) and devin/grok-4-6 (500k context, xAI).
- Support gemini38Efforts (low/medium/high) and grok46Efforts (low/medium/high/xhigh) in ResolveDevinChatModelUID, supporting both colon and parenthesis suffix parsing.
- Recognize Gemini Tink thought signatures (AY-prefix / 0x01 Tink header) in detectSignatureType and parseSignatureBytes.
- Add unit tests for both models in registry and devin_models.