- **Breaking:** the maintained Z.ai Coding catalog now contains only GLM 5.3
  and GLM 5.3 Flash. `KnownModels` no longer advertises legacy Coding Plan
  models, and `LookupModel` no longer supplies their context or reasoning
  metadata. Move Coding Plan configuration to `glm-5.3` or `glm-5.3-flash`.
- GLM 5.3 retains validated low, high, and max reasoning effort controls. GLM
  5.3 Flash preserves tool-loop thinking but does not advertise numeric or
  disabling controls.