feat: Add internal chat system and network access support

- Add messages table schema with soft delete support
- Add message service, controller and routes
- Update CORS to allow local network IPs
- Update server to listen on 0.0.0.0
- Fix cookie sameSite for local network development

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/routes/message.routes.js

@@ -0,0 +1,45 @@
+import express from 'express';
+import * as messageController from '../controllers/message.controller.js';
+import { authenticate } from '../middlewares/auth/authMiddleware.js';
+import { validateBody, validateParams } from '../middlewares/security/validateInput.js';
+import { z } from 'zod';
+
+const router = express.Router();
+
+// All message routes require authentication
+router.use(authenticate);
+
+// Get all conversations
+router.get('/conversations', messageController.getConversations);
+
+// Get all CRM users available for chat
+router.get('/users', messageController.getChatUsers);
+
+// Get unread message count
+router.get('/unread-count', messageController.getUnreadCount);
+
+// Get messages with specific user
+router.get(
+  '/conversation/:userId',
+  validateParams(z.object({ userId: z.string().uuid() })),
+  messageController.getConversation
+);
+
+// Send a message
+router.post(
+  '/send',
+  validateBody(z.object({
+    receiverId: z.string().uuid('Neplatný formát user ID'),
+    content: z.string().min(1, 'Správa nemôže byť prázdna').max(5000, 'Správa je príliš dlhá'),
+  })),
+  messageController.sendMessage
+);
+
+// Delete conversation
+router.delete(
+  '/conversation/:userId',
+  validateParams(z.object({ userId: z.string().uuid() })),
+  messageController.deleteConversation
+);
+
+export default router;