Publish Transcripted 1.1.51 release metadata

[r3dbars]

Summary

• bump the protected-main bundle metadata to 1.1.51
• add the signed Sparkle 1.1.51 appcast item
• update the Homebrew cask to the real published DMG checksum
• refresh deterministic release-health fixtures and their docs/test references

Verified release asset

• release: https://github.com/r3dbars/transcripted/releases/tag/v1.1.51
• asset: Transcripted-1.1.51.dmg
• size: 513180261 bytes
• SHA-256: 7c4e08866a587e4fd99e00860dd2803810d438dfa8845acf799b8345e8a7f029
• appcast enclosure URL, length, Sparkle signature, and Homebrew checksum match that GitHub asset
• read-only notarization, Gatekeeper, Sentry release, and matching dSYM checks passed

Validation

Current exact-head proof:

• git diff --check origin/main...origin/codex/release-1.1.51-20260724
• python3 scripts/release/post-dmg-release-audit.py --version 1.1.51 — Overall OK
• deterministic release-health fixture — 100/100
• bash scripts/release/verify-sparkle-release.sh 1.1.51 — PASS
• independent codex review --base origin/main — clean; no accepted findings
• Repo Hygiene — PASS
• Swift CI fast tests + E2E smoke — PASS
• Swift package tests + integration smoke + tools package tests — PASS
• app build + performance budget — PASS
• required aggregate build-and-test — PASS
• hardware smokes — SKIPPED/UNKNOWN

Release-time proof on this exact signed artifact also included packaged smoke 26/26 and the full repository gate 13,393 passed. No local app or release artifact rebuild was run for this metadata repair.

Merge boundary

Do not merge without explicit authorization.