[Sebastiangmz]

Summary

• Add hybrid vector + lexical retrieval with score breakdowns, path/name boosts, overlap dedupe, and deterministic budget caps.
• Add retrieval-only ContextPack models and service seam.
• Expose context packs through REST, MCP tools, and CLI.
• Extend CI/EvalFly gates for Milestone 4.

Verification

• PYTHONPATH=src .venv/bin/python -m pytest tests/test_m0_baseline.py tests/test_m1_services.py tests/test_m2_registry.py tests/test_citations.py tests/test_m3_citations.py tests/test_api_routes.py tests/test_mcp_handlers.py tests/test_mcp_tools.py tests/test_ui_handlers.py tests/test_m4_hybrid_retrieval.py
• .venv/bin/ruff check ...
• PYTHONPATH=src .venv/bin/mypy ...
• python -m py_compile ...
• python scripts/evalfly_smoke.py --suite smoke
• .venv/bin/python -m build

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