feat: add tab navigation, text cleanup and avatar caching

[huanglvjing]

Tab Navigation Support：
Support using the Tab key in the input area to trigger AI-powered text optimization, enabling faster, mouse-free editing.
Text Organization Feature：
Added a text optimization button that automatically organizes the full content, helping technical teammates understand and respond more quickly.
Avatar Caching Mechanism：
Implemented local caching for avatars and user information to reduce redundant network requests and speed up loading performance.

[github-actions]

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