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/stores/voiceStore.js

@@ -6,6 +6,7 @@ export const useVoiceStore = create((set, get) => ({
     isDeafened: false,
     isCameraOn: false,
     isScreenSharing: false,
+    participants: [],
     setVoiceUsers: (channelId, userIds) => {
         set((state) => {
             const newMap = new Map(state.voiceUsers);
@@ -32,7 +33,8 @@ export const useVoiceStore = create((set, get) => ({
         });
     },
     setCurrentVoiceChannel: (channelId) => set({ currentVoiceChannelId: channelId }),
-    toggleMute: () => set((state) => ({ isMuted: !state.isMuted })),
+    setParticipants: (participants) => set({ participants }),
+    toggleMic: () => set((state) => ({ isMuted: !state.isMuted })),
     toggleDeafen: () => set((state) => ({ isDeafened: !state.isDeafened })),
     toggleCamera: () => set((state) => ({ isCameraOn: !state.isCameraOn })),
     toggleScreenShare: () => set((state) => ({ isScreenSharing: !state.isScreenSharing })),