Add avatar of server database version upload to S3, removing SSO dependency for avatar management

[RICHQAQ]

💻 变更类型 | Change Type

• ✨ feat
• 🐛 fix
• ♻️ refactor
• 💄 style
• 👷 build
• ⚡️ perf
• 📝 docs
• 🔨 chore

🔀 变更说明 | Description of Change

This PR introduces a feature that allows direct upload of avatars to S3 for the server database version. Previously, avatar changes had to be made through the SSO provider, which was a cumbersome process. With the new implementation, users can now upload avatars directly to S3 and store the image URL in the database, removing the SSO dependency for avatar management. Other data will still remain synchronized with the SSO provider.

📝 补充信息 | Additional Information

No other functionality was affected. Only the avatar-related mechanism has been modified, making the process more efficient and user-friendly.

[lobehubbot]

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[vercel]

@RICHQAQ is attempting to deploy a commit to the LobeChat Desktop Team on Vercel.

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[RICHQAQ]

I believe that some information, such as avatars, doesn’t need to be tightly synced with the SSO provider. Just like many apps (e.g., WeChat, Google login), the username and avatar can be modified directly by the user without affecting the authentication service. This separation allows for a more flexible and user-friendly experience.

[arvinxx]

Thanks for your contribution! There is some part need to be improved~

[arvinxx]

Loading shouldn't use message loading. need another uploading ui

[RICHQAQ]

It has been changed to use the Spin to indicate the uploading process. Is this approach feasible?

[arvinxx]

should use userAvatar first and then fallback to next-auth

[RICHQAQ]

I previously used: avatar: userAvatar || nextUser.image || ''.

However, I noticed a user experience issue: when refreshing the page after updating the avatar, since nextUser.image still maintains the old value, there would be a momentary flash - showing the old avatar briefly before switching to the updated one.

I considered two solutions:

1. Use userAvatar directly while skipping nextUser.image, since during initial page load, useInitUserState reads the latest avatar from the database and saves it to the Store, which basically ensures userAvatar's availability. I've tested this and found no bugs.
2. Synchronously update nextUser.image when the avatar is updated.

I chose the first, as nextUser.image should preserve the original data from the identity provider, while custom uploaded avatars are provided through userAvatar.

If the reviewer thinks another implementation approach would be better, or has a better solution, I'm happy to make the corresponding adjustments.