Add enum package to framework

[coisa]

Problem

The framework repository does not yet include the new enum package and must add it as a dependency.

Proposal

Add the fast-forward/enum package to framework in a dedicated follow-up task, after Issue 1 (dev-tools assets sync) is validated.

Proposed Execution Plan

1. Update composer.json to include fast-forward/enum in the appropriate dependency section.
2. Install/update lockfile.
3. Verify build/tests and basic integration points.
4. Validate release/changelog impact and document usage where needed.

Acceptance Criteria

• fast-forward/enum is added to framework dependencies.
• Lockfile is updated accordingly.
• CI/tests remain stable after the addition.
• Release/changelog metadata reflects the package addition.