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/server/src/routes/utils.ts

@@ -0,0 +1,42 @@
+import type { FastifyInstance } from 'fastify';
+import { authenticate } from '../utils/auth.js';
+import * as cheerio from 'cheerio';
+
+export async function utilRoutes(app: FastifyInstance): Promise<void> {
+  app.get<{ Querystring: { url: string } }>('/api/utils/metadata', {
+    preHandler: authenticate,
+  }, async (request, reply) => {
+    const { url } = request.query;
+
+    if (!url) {
+      return reply.code(400).send({ error: 'URL is required' });
+    }
+
+    try {
+      const response = await fetch(url, {
+        headers: {
+          'User-Agent': 'OpencordBot/1.0',
+        },
+      });
+
+      if (!response.ok) {
+        throw new Error('Failed to fetch URL');
+      }
+
+      const html = await response.text();
+      const $ = cheerio.load(html);
+
+      const metadata = {
+        title: $('meta[property="og:title"]').attr('content') || $('title').text(),
+        description: $('meta[property="og:description"]').attr('content') || $('meta[name="description"]').attr('content'),
+        image: $('meta[property="og:image"]').attr('content'),
+        siteName: $('meta[property="og:site_name"]').attr('content'),
+        url: url,
+      };
+
+      return reply.code(200).send(metadata);
+    } catch (err) {
+      return reply.code(200).send({}); // Fail silently with empty object
+    }
+  });
+}