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/serverStore.js

@@ -5,10 +5,18 @@ export const useServerStore = create((set, get) => ({
     currentServerId: null,
     channels: [],
     members: [],
+    roles: [],
+    folders: [],
+    dmChannels: [],
     setServers: (servers) => set({ servers }),
     setCurrentServer: (serverId) => set({ currentServerId: serverId }),
     setChannels: (channels) => set({ channels }),
     setMembers: (members) => set({ members }),
+    setRoles: (roles) => set({ roles }),
+    setDmChannels: (dmChannels) => set({ dmChannels }),
+    addDmChannel: (channel) => set((state) => ({
+        dmChannels: [channel, ...state.dmChannels.filter(c => c.id !== channel.id)]
+    })),
     loadServers: async () => {
         try {
             const servers = await api.servers.list();
@@ -25,12 +33,22 @@ export const useServerStore = create((set, get) => ({
                 currentServerId: serverId,
                 channels: detail.channels.sort((a, b) => a.position - b.position),
                 members: detail.members,
+                roles: detail.roles.sort((a, b) => b.position - a.position), // Higher position = higher in list
             });
         }
         catch {
             // Handle error silently
         }
     },
+    loadDmChannels: async () => {
+        try {
+            const dmChannels = await api.dm.list();
+            set({ dmChannels });
+        }
+        catch {
+            // Handle error silently
+        }
+    },
     createServer: async (name, icon) => {
         const server = await api.servers.create({ name, icon });
         set((state) => ({ servers: [...state.servers, server] }));
@@ -102,7 +120,7 @@ export const useServerStore = create((set, get) => ({
             members: state.members.filter(m => m.userId !== userId),
         }));
     },
-    populateFromReady: (servers) => {
+    populateFromReady: (servers, folders, dmChannels) => {
         const simpleServers = servers.map(s => ({
             id: s.id,
             name: s.name,
@@ -111,6 +129,10 @@ export const useServerStore = create((set, get) => ({
             inviteCode: s.inviteCode,
             createdAt: s.createdAt,
         }));
-        set({ servers: simpleServers });
+        set({
+            servers: simpleServers,
+            folders: folders || [],
+            dmChannels: dmChannels || []
+        });
     },
 }));