Phase 3: Polish & PWA

Backend:
- DB: reactions table, invites table, reply_to column on messages
- gateway/events.go: added REACTION_ADD, REACTION_REMOVE events
- internal/reaction/handlers.go: reaction CRUD with WebSocket broadcast
- internal/invite/handlers.go: invite creation, info, join with code
- gateway/hub.go: presence tracking with idle detection
- gateway/client.go: idle timeout support

Frontend - Social:
- TypingIndicator: real-time 'user is typing...' display
- ReactionBar: emoji reactions on messages with counts
- EmojiPicker: searchable emoji grid for reactions
- ReplyBar: quoted reply display above messages
- MentionPopup: @mention autocomplete with user list

Frontend - PWA:
- manifest.json: PWA manifest with theme color and icons
- sw.js: service worker with cache-first strategy and push support
- stores/push.ts: push notification subscription management
- InstallPrompt: 'Add to Home Screen' banner

Frontend - Mobile:
- MobileNav: bottom nav bar for mobile (servers/channels/chat/members)
- MobileDrawer: slide-out drawer with server bar + channel list
- index.html: PWA meta tags, safe area viewport

Frontend - Polish:
- ThemeToggle: dark/light mode switch with localStorage persistence
- InviteModal: generate invite links with expiry and max uses
- JoinServer: /invite/:code join flow
- stores/typing.ts: typing indicator state management
- stores/presence.ts: real-time presence tracking
- tailwind.config.js: darkMode: 'class', light mode color tokens
- styles/index.css: light mode CSS variable overrides

web/src/stores/ws.ts

@@ -2,9 +2,12 @@ import { create } from 'zustand';
 import { useMessageStore } from './message.ts';
 import { useChannelStore } from './channel.ts';
 import { useServerStore } from './server.ts';
+import { usePresenceStore } from './presence.ts';
+import { useTypingStore } from './typing.ts';
 import type { Message } from './message.ts';
 import type { Channel } from './channel.ts';
 import type { Server } from './server.ts';
+import type { UserStatus } from './auth.ts';
 
 type UnknownPayload = Record<string, unknown>;
 
@@ -147,6 +150,20 @@ export const useWebSocketStore = create<WebSocketState>((set, get) => ({
           if (server) updateServer(server);
           break;
         }
+        case 'PRESENCE_UPDATE': {
+          const { user_id, username, status } = data.payload as Record<string, string>;
+          if (user_id && username && status) {
+            usePresenceStore.getState().updatePresence(user_id, username, status as UserStatus);
+          }
+          break;
+        }
+        case 'TYPING_START': {
+          const { channel_id, user_id, username } = data.payload as Record<string, string>;
+          if (channel_id && user_id && username) {
+            useTypingStore.getState()._handleTypingEvent({ channel_id, user_id, username });
+          }
+          break;
+        }
         default:
           break;
       }