- **New:** `drivers/zaicoding` calls Z.ai Coding's OpenAI-shaped endpoint and
  applies its per-model thinking controls. `LookupModel` supplies metadata for
  GLM 4.5 Air, GLM 4.7, and GLM 5.1 through GLM 5.3.
- Tool loops now retain Z.ai `reasoning_content` and replay it with the
  assistant tool-call message on the next provider request. The generic OpenAI
  transport exposes a trusted assistant-message extension for provider drivers
  that need this behavior.
- `ReasoningEffortNone` now reaches drivers that can disable thinking but do
  not accept numeric effort grades.
- Existing OpenAI and Anthropic callers need no changes. Applications using
  Z.ai Coding should construct `zaicoding.NewDriver` and select models with
  `zaicoding.LookupModel`.