* fix(coding-agent): report edit access failures correctly closes#3894
- classify edit and edit-preview access errors by errno
- add regressions for missing, permission, and fallback cases
- document the fix in the coding-agent changelog
* chore: get rid of CHANGELOG.md entry
* refactor(coding-agent): apply review suggestions - use single error msg
* refactor(coding-agent): clean up test cases
* fix(ai): replace stale OpenRouter Llama 4 Maverick test model
- Switch OpenRouter Meta test model from `meta-llama/llama-4-maverick` to `meta-llama/llama-4-scout` in AI tests.
- CI failure body:
- packages/ai/test/context-overflow.test.ts(531,41): error TS2345: Argument of type "meta-llama/llama-4-maverick" is not assignable to parameter of type "...".
- packages/ai/test/total-tokens.test.ts(520,40): error TS2345: Argument of type "meta-llama/llama-4-maverick" is not assignable to parameter of type "...".
* chore(ai): add changelog entry for OpenRouter test model swap
- Add Unreleased Fixed entry for switching OpenRouter Meta test model to llama-4-scout
- Reference PR #3421 attribution