Publish the first verified Skilldeck package release

[Scriptception]

Problem

The repository is mature enough for use but the README says the package is not on PyPI, while version 0.3.0 and a large Unreleased section exist without any GitHub tag or release.

User outcome

Users can install one immutable, documented Skilldeck version through normal isolated Python tool workflows.

Scope

• Choose the release version from the accumulated Unreleased changes.
• Run release preparation, plugin generation, lock refresh, tests, and consistency checks.
• Verify trusted publishing configuration and publish a release candidate before the final tag.
• Update installation documentation and rollback guidance.

Non-goals

• Adding new skills during release preparation.
• Changing adapter formats without separate compatibility work.

Acceptance criteria

• Package version, changelog, tag, wheel metadata, and generated plugin tree agree.
• The wheel and source distribution install and run in clean Python 3.10 and 3.14 environments.
• The package is discoverable through PyPI and a GitHub release contains matching notes.
• Documented uvx and isolated tool installation commands work.

Validation

• Install from the published artifacts without a source checkout.
• Run list, show, install, status, update, and uninstall smoke tests.

Relationships

• Depends on release consistency checks already present.
• Pairs with Add release provenance SBOM and installation verification.