feat: support .markdown alongside .md

[rubdos]

Very much vibe coded with GLM 5.2 (mainly to find all the necessary change locations), but seems trivial enough.

[graphify-labs]

Looks safe to merge — no coupling regressions and no blocking issues, checked against the code graph (not a self-assessment).

Graphify reviewed this change.

Looks safe to merge — no coupling regressions and no blocking issues, checked against the code graph (not a self-assessment).

---

Graphify review — findings

This pull request adds .markdown as a recognized file extension across several modules in the graphify tool. It updates the document-type classification in callflow_html.py and detect.py, the hook source extensions list in cli.py, and the extraction dispatch table in extract.py to map .markdown files to the existing markdown handler. The change extends existing .md/.mdx handling to also cover the .markdown suffix.

No blocking issues surfaced.

Analysis details — impact, health, verification

Impact & health

Graphify review

Impact — 1790 functions depend on the 463 functions this change touches.

Health — grade A; 10 existing hotspot(s) in the area this change touches (pre-existing, not introduced here):

• extract() — 359 callers, 29 callees (high)
• _rebuild_code() — 68 callers, 49 callees (high)
• detect() — 82 callers, 11 callees (high)
• extract_files_direct() — 15 callers, 19 callees (high)
• extract_xaml() — 19 callers, 12 callees (high)
• dispatch_command() — 2 callers, 110 callees (high)
• write_callflow_html() — 7 callers, 24 callees (high)
• _get_extractor() — 24 callers, 6 callees (high)
• …and 2 more

Verification — 1790 functions in the blast radius were not formally verified this run (proofs are advisory here).

Gate & verification

graphify gate

PASS — objectively clean (no health regressions, tests not run — proofs not run this pass (advisory)). Grounded, not self-assessed.

Advisory (not blocking):

• verification_scope: 1710 function(s) in the blast radius were not formally verified this run