Establish the v2.0.0 release line and enforce trustworthy version invariants

[codeforester]

Parent: #214

Train position: 1 of 26
Phase: P0 — Trustworthy runtime and release baseline

Problem

No v2.0.0 GitHub Release or remote tag exists today, but a short-lived July 2026 tag archive and Homebrew formula were withdrawn and corrected to v1.1.0; some local clones may retain the stale tag. Resetting to 0.x would move version ordering backward, while a breaking 1.5.0 would be silently accepted by Base's current 1.* compatibility gate. The 5/5 initiative therefore uses v2.0.0 as its explicit clean-break release line.

Acceptance criteria

• Declare v2.0.0 as the sole stable target for Roadmap: make base-bash-libs a 5/5 professional Bash framework #214; explicitly rule out a stable v1.5.0 and any 0.x reset; define v2.0.0-alpha.N, -beta.N, and -rc.N identifiers and the GA gate.
• Document the withdrawn July 2026 tag archive and Homebrew formula, their correction to v1.1.0, and the absence of a current remote v2.0.0 ref or GitHub Release without obscuring or rewriting the repository history.
• Make v2 the only supported line after GA across Git tags, GitHub Releases, VERSION, README, changelog, support docs, Homebrew metadata, and generated artifacts; identify 0.x and 1.x as historical and unsupported.
• Distinguish unreleased checkouts and every v2 prerelease from GA artifacts with traceable version, commit, dirty-state, and build provenance.
• Pin installation, source-checkout, vendoring, and prerelease-validation instructions to an immutable prerelease tag, verified artifact, or full commit.
• Publish a canonical v2.0.0 release asset with checksums and provenance, and make Homebrew consume that asset rather than the previously used automatic archive/refs/tags/v2.0.0.tar.gz URL.
• Make release tooling reject new stable 0.x or 1.x releases, reject unexpected local or remote v2.0.0 refs before final tag creation, and reject v2.0.0 GA until the required Roadmap: make base-bash-libs a 5/5 professional Bash framework #214 engineering, policy, documentation, artifact, and first-party release-candidate gates pass.
• Add automated checks for monotonic versions, annotated and policy-compliant tags, metadata agreement, changelog coverage, artifact identity, and conflicting or stale refs.
• Publish the release-line history, a v1.4.0-to-v2 migration inventory, and the coordinated first-party rollout tracked by Migrate first-party consumers and Homebrew to the Base Bash 2.0 contract #240; no in-library compatibility shim is required.

Dependencies

• None

[codeforester]

Foundation PR #241 merged as 3331cbc. It establishes the guarded v2 release line, immutable consumption policy, withdrawn-event history, canonical-manifest binding, adversarial release tests, and exact Bash 4.2 smoke. This issue intentionally remains open for provenance, artifact, tag/ref, and final GA rollout criteria.