feat(frontend): connect Next.js server components to Go backend REST API with resilient fallback

- Implement typed REST API client in refer_landing_page/lib/api.ts
- Support API_BASE_URL environment variable with graceful fallback to static content
- Connect Home page (projects, areas, stats), Members page (active, alumni), Publications (highlights, list, patents), Lectures, and Standardization pages to backend endpoints
- Pass all 12 SSG build, TypeScript, ESLint, and E2E quality gates

refer_landing_page/app/lectures/page.tsx

@@ -1,13 +1,16 @@
 import React from "react";
 import type { Metadata } from "next";
-import { semesters } from "../../content/lectures";
+import { semesters as staticSemesters } from "../../content/lectures";
+import { getSemesters } from "../../lib/api";
 
 export const metadata: Metadata = {
   title: "Lectures",
   description: "AI Agent Networking Lab (ANL) lecture courses and curriculum history",
 };
 
-export default function LecturesPage() {
+export default async function LecturesPage() {
+  const semesters = (await getSemesters()) ?? staticSemesters;
+
   const recentSemesters = semesters.slice(0, 3);
   const olderSemesters = semesters.slice(3);