VSTD 1.2.0: publish bounded branch-coverage evidence

[TimeLordRaps]

Coordinate

VSTD 1.2.0 release-candidate engineering evidence. This issue must not expand pull request #20 or
turn a coverage percentage into a correctness or conformance claim.

Current evidence

A local branch-aware run over src/verifier at the version 1.2.0 candidate measured 83%
overall coverage. Lower-coverage surfaces included the Advanced Micro Devices adapter,
NVIDIA adapter, core receipt handling, hardware validation, and public command-line
interface. This is a test-observation coordinate, not proof that covered behavior is correct.

Target

• Add a pinned test dependency and continuous integration (CI) command that emits branch
  coverage as a retained artifact or job summary.
• Publish component-level results so the aggregate cannot hide weak critical surfaces.
• Add targeted adversarial tests where uncovered behavior carries verification or failure
  semantics.
• Do not add a badge or blocking threshold until repeatability and component baselines are
  established.

Exit criteria

• Coverage is reproducible from a documented command.
• CI retains the report.
• Any future threshold is justified per component and cannot be met by adding low-value
  lines elsewhere.
• Coverage is never described as proof of correctness, completeness, or conformance.

[TimeLordRaps]

Implemented in stacked pull request #27 at d941df4.

Evidence:

• Coverage.py is pinned at 7.15.4 and runs with branch measurement over src/verifier.
• Continuous integration publishes JSON/XML artifacts and prints the per-file report; no badge or global percentage gate was introduced.
• Adversarial core-receipt tests now reject claim/result tampering.
• Local exact run: 402 tests passed, 83% aggregate, 70 files, 2,183 covered branches, and 863 missing branches. These are engineering coverage observations, not correctness or conformance.
• Hosted coverage job passed and retained branch-coverage-python-3.12 in run 33038825743.

The issue remains open for review and will be resolved by landing #27 rather than by leaving the work as a deferred note.