fix: update app target and improve notification handling

- Change APP_TARGET to new server address
- Add line break support in notification messages
- Include response details in webhook test notifications
- Add Content-Type header to webhook requests

vite.config.js

@@ -1,7 +1,7 @@
 import { defineConfig } from 'vite'
 import vue from '@vitejs/plugin-vue'
 
-const APP_TARGET = '192.168.1.19:19090'
+const APP_TARGET = '192.168.20.4:19090'
 
 export default defineConfig({
     define: {