fix: hide CherryIN manual model add button

[zhibisora]

What this PR does

Before this PR: CherryIN provider settings showed the manual add-model button next to the model list fetch/manage button.

After this PR: CherryIN provider settings hide the manual add-model button while keeping model list fetch/manage available.

Fixes # None

Why we need it and why it was done in this way

The following tradeoffs were made: The change is limited to the provider model list action buttons so CherryIN OAuth and model sync flows remain unchanged.

The following alternatives were considered: Disabling all add actions in the manage model dialog was considered, but the requested scope was only to remove the manual add-model button.

Links to places where the discussion took place: N/A

Breaking changes

None.

If this PR introduces breaking changes, please describe the changes and the impact on users.

Special notes for your reviewer

Testing: pnpm format, pnpm lint, and pnpm test passed. pnpm lint reported an existing React hooks warning in ManageModelsPopup.tsx and exited successfully.

Checklist

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Approvers are expected to review this list.

• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Documentation: A user-guide update was considered and is present (link) or not required. Check this only when the PR introduces or changes a user-facing feature or behavior.
• Self-review: I have reviewed my own code (e.g., via /gh-pr-review, gh pr diff, or GitHub UI) before requesting review from others

Release note

Hide the manual add-model button for CherryIN providers in model settings.

[eeee0717]

This comment was translated automatically.

Is this change necessary?

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Original Content

这个改动是有必要的吗？

[zhibisora]

This comment was translated automatically.

Is this change necessary?

This was already clarified in the meeting. Users often manually fill in the model thinking it can be used, but in fact the model ID is completely wrong. This brings significant explanation costs and causes users more frustration, thinking the service is unavailable after purchase.

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Original Content

This comment was translated automatically.这条评论已被自动翻译。

Is this change necessary?这种改变有必要吗？

Original Content 原创内容
这个改动是有必要的吗？

会议上已经明确。用户经常将模型手动填写进去就以为这个模型可以用了，但事实上模型ID完全是错误的，这带来了较大的解释成本，并且使得用户有更多挫败感，认为服务购买后不可用。