- Remove About link and sponsor notice icon from chat panel header
- Remove language switcher (English | 中文 | 日本語) from all about pages
- Fix About link in settings dialog to use current language
- Remove unused sponsorTooltip translation key from all dictionaries
* feat: add doubao provider and ByteDance sponsorship
- Add doubao provider using DeepSeek SDK with Volcengine base URL
- Add ByteDance Doubao sponsorship acknowledgment to about pages
- Update all README files (EN/CN/JA) with K2-thinking model info
- Update ai-providers.md with doubao configuration
- Keep both gateway and doubao providers after merge
* style: auto-format with Biome
* feat: add doubao and sglang to provider config panel
* fix: add doubao and sglang to validate-model API and logo maps
* docs: update ByteDance sponsorship note in all README versions
* docs: add Doubao logo to sponsorship note
* fix: use raw GitHub URL for Doubao logo in READMEs
* fix: separate link and image in sponsorship note
* fix: use PNG instead of SVG for Doubao logo
* fix: use current branch for PNG URL (will update to main after merge)
* docs: reorganize Deployment section and update image URLs to main
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Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>