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/components/voice/VoiceControls.js

@@ -7,7 +7,7 @@ export function VoiceControls({ onDisconnect, onToggleMic, onToggleCamera, onTog
     const isDeafened = useVoiceStore((s) => s.isDeafened);
     const isCameraOn = useVoiceStore((s) => s.isCameraOn);
     const isScreenSharing = useVoiceStore((s) => s.isScreenSharing);
-    const toggleMute = useVoiceStore((s) => s.toggleMute);
+    const toggleMic = useVoiceStore((s) => s.toggleMic);
     const toggleDeafen = useVoiceStore((s) => s.toggleDeafen);
     const toggleCamera = useVoiceStore((s) => s.toggleCamera);
     const toggleScreenShare = useVoiceStore((s) => s.toggleScreenShare);
@@ -17,7 +17,7 @@ export function VoiceControls({ onDisconnect, onToggleMic, onToggleCamera, onTog
     const channel = channels.find(c => c.id === currentVoiceChannelId);
     const channelName = channel?.name ?? 'Voice Channel';
     const handleMic = () => {
-        toggleMute();
+        toggleMic();
         onToggleMic();
     };
     const handleDeafen = () => {