Replace bare-pypdf/python-docx/BeautifulSoup extraction with Markdown-
preserving parsers so the chunker can split on real heading boundaries
instead of running paragraphs together.
Parsers
- pdf.py: pymupdf + pymupdf4llm.to_markdown() per page; pypdf kept as
fallback when pymupdf can't open the file.
- docx.py: mammoth.convert_to_html() + markdownify, with an explicit
style_map so Title/Heading 1..6 become h1..h6 in the output.
- html.py: BeautifulSoup pre-scrub (drop script/style) then markdownify
so <h*>, <table>, <ul> convert faithfully.
- text.py: signature update only; TXT/MD pass through unchanged.
- parsers/__init__.py: new ParsedImage + ParseResult dataclass; parse()
signature is now parse(path, *, want_images=False) -> ParseResult.
ParseResult is iterable over .pages for backward compat.
Chunker
- chunking.py: prepend Markdown heading separators ("\n# " .. "\n#### ")
to the priority list so heading-aware splits happen for free once the
parsers emit Markdown.
Ingestion
- ingestion.py: single call site updated to consume ParseResult.pages.
Deps (no-torch-runtime.txt)
+ pymupdf>=1.24, pymupdf4llm>=0.0.17, mammoth>=1.7, markdownify>=0.13
- pypdf kept as a fallback path.
Tests
- test_rag_parsers.py asserts Markdown headings survive PDF/DOCX/HTML
extraction; also exercises ParseResult iteration backward-compat.
- test_rag_chunking.py: new case verifying chunks start at Markdown
heading boundaries when the input is Markdown.
Foundation for Phase 3B-late (heading-aware spans for late chunking)
and Phase 3B-multimodal (want_images=True enables image extraction in
the same parser layer). No schema or opt-in flags in this commit.
c4b5889e53