- Fix i18next interpolation from {var} to {{var}} format in en.json
- Add gemini_base_url_label translation key for better form labeling
- Add virtual auth file and model list related translations
- Adjust UsagePage title font size to 28px for consistency
- Add ampcodeApi service for upstream URL, API key, and model mappings management
- Implement Ampcode configuration modal in AiProvidersPage
- Add complete i18n translations for Ampcode features (en and zh-CN)
- Enhance UsagePage with mobile-responsive chart improvements and legend display
- Optimize chart rendering for smaller screens
- Improve page layout styles (SystemPage, AiProvidersPage alignment)