Update frontend host and backend domain defaults for deployment.

Allow preview host mc.rc707blog.top and switch default backend base URL to https://mcbc.rc707blog.top to match domain-based runtime access.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/.env.example

@@ -1 +1 @@
-VITE_BACKEND_BASE_URL=http://127.0.0.1:14620
+VITE_BACKEND_BASE_URL=https://mcbc.rc707blog.top

frontend/src/api/backendApi.js

@@ -1,4 +1,5 @@
-const API_BASE_URL = import.meta.env.VITE_BACKEND_BASE_URL || "http://127.0.0.1:14620";
+const API_BASE_URL =
+  import.meta.env.VITE_BACKEND_BASE_URL || "https://mcbc.rc707blog.top";
 
 async function request(path, options = {}) {
   const response = await fetch(`${API_BASE_URL}${path}`, options);

frontend/vite.config.js

@@ -7,4 +7,9 @@ export default defineConfig({
   server: {
     port: 14621,
   },
+  preview: {
+    host: "0.0.0.0",
+    port: 14621,
+    allowedHosts: ["mc.rc707blog.top"],
+  },
 })