Frontend:
- Add Discord-style 3-column layout (server icons / channel sidebar / chat)
- AI Studio design system: new CSS token palette (--room-* vars)
- Replace all hardcoded Discord colors with CSS variable tokens
- Add RoomSettingsPanel (name, visibility, AI model management)
- Settings + Member list panels mutually exclusive (don't overlap)
- AI models shown at top of member list with green accent
- Fix TS errors: TipTap SuggestionOptions, unused imports, StarterKit options
- Remove MentionInput, MentionPopover, old room components (废弃代码清理)
Backend:
- RoomAiResponse returns model_name from agents.model JOIN
- room_ai_list and room_ai_upsert fetch model name for each config
- AiConfigData ws-protocol interface updated with model_name
Note: RoomSettingsPanel UI still uses shadcn defaults (未完全迁移到AI Studio)
Backend:
- Add MENTION_TAG_RE matching new `<mention type="..." id="...">label</mention>` format
- Extend extract_mentions() and resolve_mentions() to parse new format (legacy backward-compatible)
Frontend:
- New src/lib/mention-ast.ts: AST types (TextNode, MentionNode, AiActionNode),
parse() and serialize() functions for AST↔HTML conversion
- MentionPopover: load @repository: from project repos, @ai: from room_ai configs
(not room members); output new HTML format with ID instead of label
- MessageMentions: use AST parse() for rendering (falls back to legacy parser)
- ChatInputArea: insertMention now produces `<mention type="user" id="...">label</mention>`
- RoomParticipantsPanel: onMention passes member UUID to insertMention
- RoomContext: add projectRepos and roomAiConfigs for mention data sources
