feat: add DELETE /api/chat/:caseId to clear a case's chat history

Frontend's chat history trash icon was calling this endpoint but it
didn't exist yet, causing a JSON-parse error on the default 404 page.

Also renames the LegalOS health-check message to AyrisLegal.

src/controllers/chat.controller.ts

@@ -2,6 +2,24 @@ import { Response } from 'express';
 import { supabase } from '../lib/supabase';
 import { AuthenticatedRequest } from '../middleware/auth';
 
+export const deleteChatHistory = async (req: AuthenticatedRequest, res: Response) => {
+  try {
+    const { caseId } = req.params;
+    if (!caseId || caseId === 'general') {
+      return res.status(400).json({ error: 'Geçersiz caseId' });
+    }
+    // requireAuth zaten bu caseId'nin isteği yapan kullanıcıya ait olduğunu doğruladı.
+    // Silme işlemi burada (backend'de, service_role ile) yapılıyor — frontend'in anon
+    // client'ı chat_messages'a RLS nedeniyle yazamıyor/silemiyor olabilir.
+    const { error } = await supabase.from('chat_messages').delete().eq('case_id', caseId);
+    if (error) throw error;
+    res.json({ ok: true });
+  } catch (error: any) {
+    console.error('Delete Chat History Error:', error);
+    res.status(500).json({ error: error.message || 'Internal Server Error' });
+  }
+};
+
 export const chatMessage = async (req: AuthenticatedRequest, res: Response) => {
   try {
     const { caseId } = req.params;

src/routes/chat.routes.ts

@@ -1,9 +1,10 @@
 import { Router } from 'express';
 import { requireAuth } from '../middleware/auth';
-import { chatMessage } from '../controllers/chat.controller';
+import { chatMessage, deleteChatHistory } from '../controllers/chat.controller';
 
 const router = Router();
 
 router.post('/:caseId/message', requireAuth, chatMessage);
+router.delete('/:caseId', requireAuth, deleteChatHistory);
 
 export default router;

src/routes/index.ts

@@ -6,7 +6,7 @@ import precedentRoutes from './precedent.routes';
 const router = Router();
 
 router.get('/health', (req, res) => {
-  res.json({ status: 'ok', message: 'LegalOS Backend is running' });
+  res.json({ status: 'ok', message: 'AyrisLegal Backend is running' });
 });
 
 router.use('/documents', documentRoutes);