Add test coverage for paths.nfc()

[hshalwhabi-cpu]

Summary

• graphify.paths.nfc() normalizes path strings to NFC to keep macOS's NFD filenames matching NFC entries in manifests/graphs (see Incremental extract() false-positives unchanged files as "deleted", silently pruning valid nodes #2210, macOS: --update re-extracts everything when corpus path has non-ASCII chars (NFC/NFD manifest mismatch) #2221/fix(detect): NFC-normalize manifest keys for macOS --update #2224), but had no direct unit test.
• Adds a small test asserting a decomposed (NFD) string normalizes to its precomposed (NFC) form, and that already-NFC input is a no-op.

Test plan

• pytest tests/test_paths.py -v — 50 passed locally

[graphify-labs]

Graphify reviewed this change.

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

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Graphify review — findings

Adds a test for nfc in tests/test_paths.py, verifying it normalizes NFD (decomposed) unicode to NFC and leaves already-NFC input unchanged. Imports nfc from graphify.paths.

No blocking issues surfaced.

Analysis details — impact, health, verification

Impact & health

Graphify review

Impact — 13 functions depend on the 13 functions this change touches.

Health — grade A; no new coupling hotspots.

Verification — 13 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: 13 function(s) in the blast radius were not formally verified this run