Add chat features: mentions, pins, bookmarks, search, presence & more

[TechHutTV]

Summary

Adds 10 features to the chat system to bring it closer to a Slack-like experience. Spans backend (service/controller/routes), frontend (components/hooks/api), shared schemas, and a new Prisma migration.

Features

@Mentions

• @ trigger in message input with member dropdown picker and keyboard navigation
• Stores @[userId] format internally, renders as highlighted @DisplayName
• Creates CHAT_MENTION notifications for mentioned users

Chat Notifications

• New CHAT_MENTION and CHAT_DM_MESSAGE notification types
• DM messages auto-notify all other channel members
• Notification preference toggles for both types in settings
• Real-time delivery via WebSocket notification_created event

Markdown Rendering

• Messages render markdown (bold, italic, code, links, lists) via react-markdown + remark-gfm
• Mentions are pre-processed into bold @DisplayName before rendering

File Sharing

• Paperclip button on message action toolbar opens Drive file picker
• Reuses existing Attachment model with entityType="message"

Pinned Messages

• Pin/unpin messages from the action toolbar
• Pin count badge and panel accessible from channel header
• Real-time updates via chat_message_pinned/chat_message_unpinned events

Bookmarks / Saved Messages

• Bookmark button on message action toolbar
• "Saved Messages" entry in channel sidebar opens bookmarks panel
• Per-user saved messages with channel context

Thread Subscriptions

• Auto-subscribe when replying to a thread
• Bell icon toggle in thread panel header for manual subscribe/unsubscribe
• Subscribers notified of new replies via WebSocket

Message Search

• Global (Cmd+K): Chat messages appear alongside tasks and wiki pages in search results
• In-channel: Search icon in channel header opens a search bar with results dropdown

Presence (Online/Away/Offline)

• WebSocket-based presence using existing connection tracking (5-min away threshold)
• Green/yellow dots on DM avatars in sidebar
• Presence status shown in DM channel headers
• presence_online/presence_offline broadcast events

Channel Archiving

• Archive/unarchive from channel settings dialog
• Archived channels show banner, hide message input, block new messages
• Collapsed "Archived" section in sidebar
• Real-time archive/unarchive events

Schema Changes (single migration)

• ChatChannel: + archivedAt, archivedById
• ChatMessage: + pinnedAt, pinnedById
• NotificationType enum: + CHAT_MENTION, CHAT_DM_MESSAGE
• NotificationPreference: + chatMention, chatDmMessage
• New table: ChatBookmark (userId + messageId, unique constraint)
• New table: ChatThreadSubscription (messageId + userId, unique constraint)

Files Changed

• 32 files across backend, frontend, shared, and prisma
• +2,339 lines / -86 lines