tech debt #264: fix core -> providers import direction

[sonikro]

Summary

Fixes tech debt issue #264 by correcting dependency direction in core use cases.

Changes

Updated ServerManagerFactory imports in core use cases from @tf2qs/providers to @tf2qs/core:

• packages/core/src/usecase/CreateServerForUser.ts
• packages/core/src/usecase/DeleteServer.ts
• packages/core/src/usecase/DeleteServerForUser.ts
• packages/core/src/usecase/TerminateLongRunningServers.ts
• packages/core/src/usecase/TerminatePendingServers.ts
• packages/core/src/usecase/TerminateServersWithoutCredit.ts

Why

Core should not depend on providers in Clean Architecture. This change keeps dependency flow inward and uses the interface re-exported by core.

Closes #264

[Copilot]

Pull request overview

This PR addresses tech debt by correcting core use case imports so they no longer depend on the providers package for ServerManagerFactory.

Changes:

• Replaced @tf2qs/providers imports with @tf2qs/core in six core use cases.
• Keeps dependency direction aligned with the intended core/provider layering.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
packages/core/src/usecase/CreateServerForUser.ts	Updates ServerManagerFactory import source.
packages/core/src/usecase/DeleteServer.ts	Updates ServerManagerFactory import source.
packages/core/src/usecase/DeleteServerForUser.ts	Updates ServerManagerFactory import source.
packages/core/src/usecase/TerminateLongRunningServers.ts	Updates ServerManagerFactory import source.
packages/core/src/usecase/TerminatePendingServers.ts	Updates ServerManagerFactory import source.
packages/core/src/usecase/TerminateServersWithoutCredit.ts	Updates ServerManagerFactory import source.