Add exact rational derived-holonomy certificates

[jkolantree]

Summary

This adds F12, an independent reconstruction over Q. It is not a historical-script replay and is not kernel verification.

• validates finite bounded chain complexes, d²=0, and both chain-map equations;
• constructs exact Ah=ω, returning rational homotopy matrices or a normalized rational left-null obstruction;
• retains one contractible positive case and one homology-visible obstruction;
• fails closed on canonical JSON, schema identity, byte reproduction, provenance, and repository namespace mismatches.

The exhaustive scalar census covers 729 raw tuples, 153 valid pairs, 81 homotopic and 72 obstructed cases, with zero mismatches.

Verification

• F12 independent checker: PASS (2 certificates)
• focused F12 tests: 16 passed
• full fixture gate: F8/F10/F11/F12 PASS
• complete unit suite: 205 passed, 1 skipped (Windows symlink privilege unavailable, WinError 1314)
• Markdown math: PASS
• manifest: PASS (101 files)
• normal checkout / linked worktree / git archive inventory: PASS (101 identical files)
• two development builds: byte-identical; detached identities PASS
• git diff --check: PASS
• fresh PDF build: unavailable because make, latexmk, pdflatex, and tectonic are absent

No paper, PDF, release, tag, DOI, Zenodo, ruleset, roadmap, or scientific-sequence mutation is included.