cargo-rail v0.29.0

• Add independently authenticated compiler adapter packs for toolchains beyond the embedded driver,
  while keeping native cache failures fail-open and Surface acquisition fail-closed.

  Strengthen release preparation with local extended checks, crate-qualified default tags,
  linked GitHub changelog comparisons, and release-record contract v10.
  Make Cargo-Rail's hosted release enforce the existing package workflow, crates.io publication,
  GitHub release, release assets, and historical v{version} tag namespace.
  Remove the no-op release.require_changelog_entries configuration field;
  release.require_release_notes remains the release-prose gate.
  Keep the remote active-release lease readable across record-schema upgrades without accepting older transaction records.
  Correct cache readiness, initialization, and dependency-unification edge cases.

• Keep saved plans valid across equivalent direct and Cargo-subcommand invocations.
  Normalize proven rustup Cargo selection while binding the selected executable bytes
  and preserving rejection of changed Cargo programs or configuration.
  Regenerate saved plans created before this fix.