* 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
cbe0e8304f