[Bug] Claude Code 2.1.9 regression: degraded code generation quality and reasoning

Question

**Bug Description**
honestly the 2.1.9 version of CC is the worst version in months since the release of opus. idk what you changed but it is bad, it's like sonnet 3.5 in github copilot without any harness

**Environment Info**
- Platform: darwin
- Terminal: Apple_Terminal
- Version: 2.1.9
- Feedback ID: 84ac5255-f220-4ec6-9255-524ddf979906

**Errors**
```json
```