feat(frontend): add repo type to mention autocomplete system

Add 'repo' to MentionType across all editor types, include repos in the
@ trigger pool, add repo badge (green chip), Repos section in the
mention dropdown, and MentionBadge styles. Wire projectRepos from
room context into IMEditor mentionItems.

src/components/room/message/MessageInput.tsx

@@ -76,7 +76,7 @@ export const MessageInput = forwardRef<MessageInputHandle, MessageInputProps>(fu
     {roomName, onSend, replyingTo, onCancelReply},
     ref,
 ) {
-    const {members, activeRoomId, roomAiConfigs, wsClient} = useRoom();
+    const {members, activeRoomId, roomAiConfigs, projectRepos, wsClient} = useRoom();
 
     // Ref passed to the inner IMEditor
     const innerEditorRef = useRef<IMEditorHandle | null>(null);
@@ -147,12 +147,18 @@ export const MessageInput = forwardRef<MessageInputHandle, MessageInputProps>(fu
         channels: [] as { id: string; label: string; type: 'channel'; avatar?: string }[],
         ai: roomAiConfigs.map((cfg) => ({
             id: cfg.model,
-            label: cfg.modelName ?? cfg.model,
+            label: cfg.modelName || 'Unknown AI',
             type: 'ai' as const,
         })),
+        repos: projectRepos.map((r) => ({
+            id: r.repo_name,
+            label: r.repo_name,
+            type: 'repo' as const,
+            description: r.description ?? undefined,
+        })),
         commands: SLASH_COMMANDS,
         specialMentions: SPECIAL_MENTIONS,
-    }), [members, roomAiConfigs]);
+    }), [members, roomAiConfigs, projectRepos]);
 
     // File upload handler — POST to /rooms/{room_id}/upload
     const handleUploadFile = async (file: File): Promise<{ id: string; url: string }> => {

src/components/room/message/editor/IMEditor.tsx

@@ -26,6 +26,7 @@ export interface IMEditorProps {
         users: MentionItem[];
         channels: MentionItem[];
         ai: MentionItem[];
+        repos: MentionItem[];
         commands: MentionItem[];
         specialMentions?: MentionItem[];
     };
@@ -151,6 +152,7 @@ function getBadge(type: MentionType): { label: string; cls: string } | null {
     if (type === 'ai') return {label: 'AI', cls: 'bg-blue-50 text-blue-600'};
     if (type === 'channel') return {label: '#', cls: 'bg-gray-100 text-gray-500'};
     if (type === 'command') return {label: 'cmd', cls: 'bg-amber-50 text-amber-600'};
+    if (type === 'repo') return {label: 'repo', cls: 'bg-green-50 text-green-600'};
     return null;
 }
 
@@ -173,12 +175,13 @@ function serializeAstNode(node: EditorNode): string {
 
 // ─── Mention Dropdown (sectioned by type) ────────────────────────────────────
 
-const SECTION_ORDER = ['special_here', 'special_channel', 'ai', 'user', 'channel', 'command'] as const;
+const SECTION_ORDER = ['special_here', 'special_channel', 'ai', 'user', 'repo', 'channel', 'command'] as const;
 const SECTION_LABELS: Record<string, string> = {
     special_here: 'Notify',
     special_channel: 'Notify',
     ai: 'AI',
     user: 'Members',
+    repo: 'Repositories',
     channel: 'Channels',
     command: 'Commands',
 };
@@ -356,7 +359,8 @@ export const IMEditor = forwardRef<IMEditorHandle, IMEditorProps>(function IMEdi
         ...(mentionItems.specialMentions ?? []),
         ...mentionItems.ai,
         ...mentionItems.users,
-    ], [mentionItems.specialMentions, mentionItems.ai, mentionItems.users]);
+        ...mentionItems.repos,
+    ], [mentionItems.specialMentions, mentionItems.ai, mentionItems.users, mentionItems.repos]);
 
     const hashPool = useMemo(() => [...mentionItems.channels], [mentionItems.channels]);
 

src/components/room/message/editor/types.ts

@@ -2,7 +2,7 @@
  * Core types for the IM editor (mentions, files, emojis).
  */
 
-export type MentionType = 'user' | 'channel' | 'ai' | 'command' | 'special_here' | 'special_channel';
+export type MentionType = 'user' | 'channel' | 'ai' | 'repo' | 'command' | 'special_here' | 'special_channel';
 
 export interface MentionItem {
   id: string;

src/components/shared/MentionBadge.tsx

@@ -42,6 +42,11 @@ const TYPE_STYLE: Record<MentionType, { light: string; dark?: string; prefix: st
     dark: 'dark:bg-orange-900/30 dark:text-orange-300',
     prefix: '@',
   },
+  repo: {
+    light: 'bg-teal-50 text-teal-600',
+    dark: 'dark:bg-teal-900/30 dark:text-teal-300',
+    prefix: '@',
+  },
 };
 
 export function MentionBadge({ type, label, onClick, id, className }: MentionBadgeProps) {

src/lib/mention.ts

@@ -7,6 +7,7 @@ export type MentionType =
   | 'user'
   | 'channel'
   | 'ai'
+  | 'repo'
   | 'command'
   | 'special_here'
   | 'special_channel';
@@ -15,6 +16,7 @@ export const MENTION_TYPES: MentionType[] = [
   'user',
   'channel',
   'ai',
+  'repo',
   'command',
   'special_here',
   'special_channel',
@@ -84,6 +86,11 @@ export function serializeAiMention(aiId: string, aiName: string): string {
   return serializeMention('ai', aiId, aiName);
 }
 
+/** Build a mention token from a repo mention. */
+export function serializeRepoMention(repoName: string, label?: string): string {
+  return serializeMention('repo', repoName, label ?? repoName);
+}
+
 /** Build a mention token from a command mention. */
 export function serializeCommandMention(commandId: string, commandName: string): string {
   return serializeMention('command', commandId, commandName);