Close release artifact and traceability proof gaps

[iperev]

Summary

Closes the confirmed release, graph, browser lifecycle, and proof-oracle gaps found in the immutable v0.1.159 audit. This prepares the v0.1.160 candidate without claiming publication.

Atomic Closure Ledger

• Wheel platform truth: Darwin wheel tags now declare macOS 12.0, and verification independently decodes Mach-O minimum OS metadata from embedded binaries.
• Wheel license closure: all wheels use Core Metadata 2.4, declare the MIT expression/file, embed the exact repository LICENSE, and bind it through RECORD.
• Graph output integrity: one typed validator owns endpoint resolution, parent/contains bijection, abstraction order, execution-node kinds, and evidence-plane relations for both Build and AdmitOutput.
• Graph source and budget closure: every supplied source digest is checked against actual content; node, edge, and source-byte budgets dominate per-item semantics.
• Graph schema evolution: input advances to schemaVersion 2 and rejects the removed topologyId field; descriptors, browser fixtures, specs, migration notes, and whole-CLI witnesses agree.
• Browser terminal integrity: one-shot success is emitted only after cleanup completes; close/serve failures are preserved.
• Browser selection authority: natural select -> focus/fill -> submit persists only as an explicit visible committed selection, and clear revokes that authority.
• Retained evidence topology: one repository-owned builder/verifier emits artifact-relative checksum paths matching the downloadable layout.
• Release contract delta: a version-bound machine record owns breaking changes, additions, migration, platform requirements, limitations, and rollback; release closeout requires byte-exact Markdown projection.
• Proof gaps: whole-CLI context/diff/graph routing, complete semantic-diff classes, Unicode code-point selection, parent topology falsifiers, and change-record drift have executable tests.

Validation

• npm run check
• go test -race ./internal/command/requirementgraph ./internal/command/requirementbrowser ./internal/app ./internal/tools/pythonpackage ./internal/tools/releasechange ./internal/tools/retainedevidence ./internal/tools/releasecloseoutinput
• go test ./internal/command/requirementbrowser -run 'TestServeOneShot' -count=20
• Browser proof: 18/18 across Chromium, Firefox, and WebKit
• Self-hosting: 68/68 requirements bound, 145 scenarios
• git diff --check
• Final wheel inspection: four expected 0.1.160 tags, exact LICENSE payloads, Core Metadata 2.4, and Mach-O minos 12.0

Two independent closure reviews found no remaining confirmed defect in the changed browser, graph, schema-evolution, and release-note surfaces.

Non-Claims

This PR does not publish npm, PyPI, or GitHub Release artifacts; prove provider-side attestation or registry state; yank v0.1.159; prove consumer rollout; or claim production readiness. The immutable v0.1.159 artifacts remain unchanged. PyPI yanking is deferred until a verified replacement is public.