Canonical paper PDF + arXiv package

The release workflow verifies all three pinned hashes, recompiles the arXiv source in a clean directory with PDFLaTeX, byte-compares all 19 rendered pages and extracted text against the canonical PDF, lints references and the sealed boundary, replays the capsule, and stamps the checksum with OpenTimestamps. The upload package contains exactly main.tex and five vector figures. Submission fields (title, abstract, cs.CL primary with cs.CY cross-list) are frozen in arxiv-metadata.txt.