Replace mocked DB/internal-services with real ChromaDB/SQLite via tmp_path.
Only mock truly external APIs (LLM, embedding for deterministic vectors).
13 test files rewritten (314 pass, 0 fail):
- Route tests: use TestClient + real ChromaDB, seed test data
- Service tests: use real PersistentClient/SQLite instances
- Pipeline tests: TestClient hits SSE /query endpoint, verify history
- Converted unittest.TestCase to pytest where applicable
Plus: fix metadata.py to filter None values from ChromaDB metadata
(pre-existing bug caught by real-DB ingestion tests)
PDF uploads now use parse_pdf_by_page() -> chunk_pages() -> extract page PDFs -> enhanced metadata with page_number, chunk_file_path, and document_id. Same-filename replacement deletes old chunks and PDFs before re-ingest. DOCX/TXT keep original flat flow with document_id added. RAGService.ingest_document() accepts optional document_id parameter.
Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)
Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>
Woody