Add chunks_retrieved_per_subq_count and chunks_filtered_per_subq_count columns to query_history table with safe ALTER TABLE migration. Replace generate template {question}/{context} placeholders with {context_sections} for per-sub-question organized context sections. Update Phase 3 test assertions to match new template and schema shapes.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Woody