v0.17.15 — maintenance: AST test rewrite + Node 24 actions bump

v0.17.15 (2026-04-26)

Maintenance release. Pure internal hardening — no API changes, no user-visible behavior changes. Two items closed from the v0.17.14-CI-hotfix backlog plus one GitHub deprecation tracker.

Changed

• tests/test_quality_gate.py: migrated test_person_path_invokes_compute_quality_flags from string-grep (Path.read_text() + str.index()) to ast.parse() walk. Same invariant (the person loop in process() must contain a Call to compute_quality_flags), but structurally rigorous — comments and string literals containing the function name no longer satisfy the assertion. Closes the codex P2 from the 2026-04-26 v0.17.14-CI-hotfix review.
• .github/workflows/ci.yml: bump actions/checkout@v4 → @v5 and actions/setup-python@v5 → @v6. GitHub will force Node.js 24 default on Actions runners 2026-06-02 and remove Node 20 entirely 2026-09-16; v4/v5 are Node-20-pinned. v5/v6 are the first majors that support Node 24.

Notes

• compute_quality_flags was extracted to vulca._quality_gate in the post-tag CI hotfix during v0.17.14 (commit b5088caa, 2026-04-26) — see retro entry below.