Make protected release plans approval-bound

[fxdv]

Product direction

Makes protected-mode safe release coordination the default product path:

• keeps patchlog release --dry-run as the universal immutable planner;
• fingerprints phase, HEAD, branch/tag identities, exact version-file changes,
  mutation targets, publication content, and provider target;
• requires approval of the exact current fingerprint before release mutation;
• separates protected prepare from finalize;
• keeps direct commit/tag/push behind release direct;
• moves AI, Confluence, metrics, and labs into focused namespaces.

Transaction and security hardening

• revalidates local and remote protected-branch state immediately before apply;
• commits only exact bump files through an isolated Git index;
• keeps multi-file bumps transactional and reports partial remote completion;
• ignores nightly/prerelease marker tags for stable phase selection;
• validates Git refs and keeps Confluence out of release transactions;
• emits content-free preflight rejection categories.

Distribution and trust loop

• publishes the live fxdv/homebrew-tap channel;
• adds automatic macOS Homebrew installation testing to releases;
• documents installation and the v0.2.0 stability contract;
• explicitly documents the Rust virtual-workspace boundary and VERSION
  workaround.

Evidence

• bash scripts/gate.sh: 8/8 checks green on Go 1.26.5;
• full Go 1.26.5 suite: green;
• full supported-minimum Go 1.22.12 suite: green with the external-linker
  workaround required by this macOS host;
• final PR head: both quality runs green;
• Homebrew sync/install/test:
  https://github.com/fxdv/homebrew-tap/actions/runs/30016485477;
• hosted Ouroboros mirror: protected PR
  https://github.com/fxdv/patchlog-validation-ouroboros/pull/1, green
  post-merge main CI
  https://github.com/fxdv/patchlog-validation-ouroboros/actions/runs/30046698904,
  and annotated v6.3.0 targeting the exact green commit;
• hosted vllm-metal mirror: protected PR
  chore(release): prepare v0.2.1 with Patchlog patchlog-validation-vllm-metal#1, green
  post-merge main CI
  https://github.com/fxdv/patchlog-validation-vllm-metal/actions/runs/30046703150,
  and annotated v0.2.1 targeting the exact green commit;
• both source repositories remained at their audited main SHAs; all mutations
  were confined to public validation mirrors;
• fxdv/demiurge virtual-workspace version detection was rejected without
  mutation and is now an explicit 0.2.x limitation.

Proxy metrics remain diagnostic, never release gates. True coverage comes from
CI artifacts; dependency risk requires language-aware graphs; lead/cycle time
requires PR and deployment timestamps.

Operational rollout

1. Merge only while PR Make protected release plans approval-bound #11 remains current, mergeable, and green under main
   protection.
2. Wait for the post-merge main quality run on the exact squash commit.
3. Dogfood protected prepare for patch v0.1.4, merge its one-file PR after
   green CI, and wait for green main again.
4. Approve the separately fingerprinted finalize plan for that exact main
   commit.
5. Require the tag-triggered trust loop to publish archives, SHA256SUMS,
   attestations, the GitHub release, and verify archive execution, @v0.1.4,
   @latest, and Homebrew installation.