- LLMClient.complete() now accepts step_name parameter to identify processing step
- Logs prompt preview (first 100 + last 100 chars) at INFO level
- Logs processing time in milliseconds with token usage stats
- Updated QueryDecomposer, RelevanceFilter, and RAGService to pass step names
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>