v1.20.0

## What's New

- **New Copilots UI**: Redesigned copilots page with featured, my copilots, and search tabs
- **Unified Model Registry**: Models now enriched with metadata from models.dev
- **Redesigned Thinking & Web Search UI**: Updated thinking and web search display per Figma specs
- **Background Image**: Only display background image in session page
- **Message Layout**: Added setup guidance and configuration for message layout
- **Sidebar UI**: Updated sidebar for small screens
- **Image Gallery**: Enhanced CopilotDetailModal with image gallery support
- **Build Channel**: Added build channel env variable for request headers
- **Supply Chain Security**: Configured pnpm minimumReleaseAge

## Bug Fixes

- Fix message layout by role and mode
- Fix case unification and model selector button
- Fix mobile sticky action bar positioning
- Fix i18n Star/Unstar translation key case
- Fix compaction toggle alignment with detector for proxy providers
- Fix reference image field name and preview display
- Fix new message placement at top
- Fix image-gen timeout and directory creation
- Fix AI SDK totalUsage for token usage display
- Fix deprecated showTokenCount display logic
- Fix screenshot preview responsiveness
- Fix window controls on Windows for guide page
- Fix Anthropic OAuth API invalid_request_error
- Fix global font size for summary message content
- Fix replaying OpenAI OAuth Responses tool items
- Fix Plausible domain for web builds

**Full Changelog**: https://github.com/chatboxai/chatbox/compare/v1.19.1...v1.20.0