A frozen spec is only meaningful if it's paired with the corpus that was current at release time — otherwise a v0.1.0 reader follows "see corpus/payloads/ack/" and lands on a file whose test vectors may have changed since v0.1.0 was cut. Three changes: 1. `cut-version` now copies BOTH src/ AND corpus/ into the snapshot directory. A release is the pair, not just the text. 2. The corpus URL rewriting in cut-version now retargets /tree/main/corpus -> /tree/main/versions/<v>/corpus (and the blob variant). This lets the link resolve on GitHub from main alone — no git tag required, since the frozen copy is a real path under main. Downgrades the "tag is REQUIRED" message from last commit back to "optionally tag the commit". 3. The frozen corpus's spec_ref fields get rewritten too: from `src/04-payload-ack.md` to `versions/<v>/04-payload-ack.md`, so a reader following a test vector lands on the spec text the vector was paired with at release time. versions/v0.1.0/ regenerated from scratch via `just cut-version v0.1.0` to pick up the corpus snapshot + the new sed patterns. The release is now self-consistent: v0.1.0 spec links go to v0.1.0 corpus, which links back to v0.1.0 spec. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>