- Updated parseChunkUsage to subtract prompt_tokens_details.cache_write_tokens from prompt token input so OpenRouter write tokens are not misclassified as billable input.
- Set cacheWrite and total token counts to include cache-write usage, while preserving cache-read behavior from existing cached_tokens handling.
- Added OpenRouter attribution tests verifying cacheWrite and cacheRead totals for write-heavy and cache-warm prompts.