feat: add template upload/download/delete endpoints

Belge Şablonları now stores real files: POST /api/templates/upload
(multer -> Supabase Storage under templates/<user>/, then a templates
row), GET /api/templates/:id/download-url (short-lived signed URL),
and DELETE /api/templates/:id. Mounted at /api/templates.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/routes/index.ts

@@ -3,6 +3,7 @@ import documentRoutes from './document.routes';
 import chatRoutes from './chat.routes';
 import precedentRoutes from './precedent.routes';
 import caseRoutes from './case.routes';
+import templateRoutes from './template.routes';
 
 const router = Router();
 
@@ -13,6 +14,7 @@ router.get('/health', (req, res) => {
 router.use('/documents', documentRoutes);
 router.use('/chat', chatRoutes);
 router.use('/cases', caseRoutes);
+router.use('/templates', templateRoutes);
 router.use('/', precedentRoutes); // Keeps the same paths like /api/search-precedents
 
 export default router;