fix: repair invite links, social features, messaging + Discord UI overhaul

Phase 1 - Feature Repair:
- Fix member kick/leave: add missing db.delete() call in servers.ts
- Stabilize invite codes: return existing code instead of regenerating
- Fix user search: use LIKE instead of exact match in social.ts
- Wire DM button on FriendsPage to create/navigate to DM channels
- Add cancel outgoing friend request (DELETE endpoint + frontend)
- Add accept/decline friend request actions with WS real-time events
- Fix replyToId persistence in message creation
- Hydrate reactions and replyTo in message queries
- Add joinByCode to API client and serverStore
- Add friend_request_received/accepted WebSocket events

Phase 2 - Discord UI Overhaul:
- Remove stray borders between layout columns
- Replace shadow-sm with shadow-header on content headers
- Replace all bg-gray-*/text-gray-* with Discord color tokens
- Ensure flat color contrast (#1E1F22, #2B2D31, #313338)

Testing:
- Set up vitest + @testing-library/react + jsdom
- Add 17 tests across InviteModal, JoinServer, FriendsPage (all passing)
- Fix vite resolve.extensions to prefer .tsx over stale .js files

packages/web/src/hooks/useWebSocket.ts

@@ -3,6 +3,7 @@ import { useAuthStore } from '../stores/authStore';
 import { useServerStore } from '../stores/serverStore';
 import { useChatStore } from '../stores/chatStore';
 import { useVoiceStore } from '../stores/voiceStore';
+import { useSocialStore } from '../stores/socialStore';
 import type { ServerEvent, ClientEvent } from '@opencord/shared';
 
 let globalWs: WebSocket | null = null;
@@ -14,13 +15,13 @@ let isInitialized = false;
 function handleEvent(event: ServerEvent): void {
   const { setUser } = useAuthStore.getState();
   const { populateFromReady, loadServerDetail, currentServerId, updateMemberPresence, addMember, removeMember } = useServerStore.getState();
-  const { addMessage, updateMessage, removeMessage, setTyping } = useChatStore.getState();
+  const { addMessage, updateMessage, removeMessage, setTyping, onReactionAdded, onReactionRemoved } = useChatStore.getState();
   const { addVoiceUser, removeVoiceUser } = useVoiceStore.getState();
 
   switch (event.type) {
     case 'ready':
       setUser(event.user);
-      populateFromReady(event.servers);
+      populateFromReady(event.servers, event.folders, event.dmChannels);
       if (currentServerId) {
         loadServerDetail(currentServerId);
       }
@@ -63,8 +64,29 @@ function handleEvent(event: ServerEvent): void {
       break;
 
     case 'dm_message_created':
+      addMessage(event.message.dmChannelId, event.message as any);
       break;
 
+    case 'reaction_added':
+      onReactionAdded(event.messageId, event.reaction);
+      break;
+
+    case 'reaction_removed':
+      onReactionRemoved(event.messageId, event.userId, event.emoji);
+      break;
+
+    case 'friend_request_received': {
+      const { addIncomingRequest } = useSocialStore.getState();
+      addIncomingRequest(event.request);
+      break;
+    }
+
+    case 'friend_request_accepted': {
+      const { addFriendFromAccepted } = useSocialStore.getState();
+      addFriendFromAccepted(event.friend, event.requestId);
+      break;
+    }
+
     case 'error':
       console.error('WebSocket error:', event.message);
       break;