Add 6 tests for retrieve_per_subquestion and generate_response_per_subquestion to Phase 1 rag service tests. Add 4 tests for filter_per_subquestion to Phase 1 relevance filter tests. Add 2 tests for new {context_sections} generate template to Phase 3 prompt injection tests. Add TestPerSubQPipelineHistory class with 3 per-sub-q pipeline simulation tests to Phase 3 integration tests. Add generate_per_subq template seed to conftest mock_prompt_service fixture.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Woody