feat: add forgejo_team_repository resource

[ap-1]

Adds a forgejo_team_repository resource for managing team-to-repository assignments.

The resource uses existing Forgejo SDK methods (AddTeamRepository, RemoveTeamRepository, ListTeamRepositories). All attributes require replacement. Import is supported using org_name/team_name/repo_name, consistent with forgejo_team.

Re #114: that issue requested a repos selector on forgejo_team at creation time, which would require SDK/API changes. This takes the dedicated join resource approach instead (cf. github_team_repository), which covers the same use case with the existing SDK.

Closes #114
Closes #154

[acch]

Hi @ap-1, thank you very much for your valuable contribution - and sorry for the delay in my response!

I like the idea of a dedicated resource to model the team <-> repo relationship. This is consistent with how we already model similar relationships, e.g. team members and repo collaborators. I like your design very much!

I do, however, have one concern: child resources (like forgejo_team_repository) referencing parent resources (forgejo_team, forgejo_repository) should generally use the numeric identifier for referencing the parent resource (with very few exceptions). Since the numeric ID is unknown at plan-time, Terraform implicitly knows that the parent resources must be created first, before the child resources can be created.

You do reference the parent team by ID (team_id) but not the parent repo (owner/repository). This means that Terraform is not aware of the dependency between the two. In fact, your example has a race condition: Terraform could attempt to create forgejo_team_repository first, before forgejo_repository is even finished...

Please reference both, team and repo by numeric ID. We already use repository_id in e.g. forgejo_repository_action_secret, forgejo_repository_webhook, and forgejo_collaborator, so I'd suggest to use the same semantics here.

For the import, however, I think that names are more appropriate than numeric identifiers. I like the current org/team/repo import identifier - no need to change that.

Do you think this makes any sense?

On a different note: I think your PR is missing acceptance tests for the new resource. Did you forget to include them?

[acch]

Hi @ap-1 - do you agree with referencing both, teams and repos by numeric ID? Do you have questions, or is there anything I can help with?