v0.47.0

• A run the queue ends names the candidate it keeps. When admission_wait runs out while a candidate is verified, the run still ends blocked (admission_wait_exhausted), and the outcome now says how to verify the candidate again without a worker: a kind: verify run naming candidate {run, index}. Its transition detail carries candidate {run, index, sha}; a kind: verify run names its source run. The attempt row is closed blocked with its sha, where it used to stay verifying. A reviewer whose admission runs out ends needs_review (review unavailable) with the same recovery in its text. The text no longer says "nothing was launched" when a worker already made the candidate.
• The release signs its attestations. CI signs the gate attestations on each push to main, and the release requires them signed.

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What's Changed

• build(ci): sign attestations on push to main by @fredericrous in #372
• fix(ci): sign job reads the leg's result file by @fredericrous in #373
• build(release): require signed attestations by @fredericrous in #374
• fix(runner): blocked runs name the kept candidate by @fredericrous in #375
• chore(release): v0.47.0 by @fredericrous in #376

Full Changelog: v0.46.0...v0.47.0