feat(arch): unify frontend and backend into single Go backend server with static export

- Configure Next.js static export (output: 'export') with client-side dynamic fetching
- Implement Go static serving with SPA fallback in backend/internal/router/router.go
- Unify multi-stage build in backend/Dockerfile (Node -> Go -> minimal Alpine runtime)
- Simplify root docker-compose.yml to single anl-app service on port 8080
- Update REQUIREMENTS.md DM-03 and AC-17 normative contracts to v3.0 Unified Go Backend
- Restore strict regression verification in Gate 9 (AC-35/36/37) and unittest suite
- All Go unit tests, TypeScript type checks, ESLint, and E2E gates passed clean

refer_landing_page/app/lectures/layout.tsx

@@ -0,0 +1,10 @@
+import type { Metadata } from "next";
+
+export const metadata: Metadata = {
+  title: "Lectures",
+  description: "AI Agent Networking Lab (ANL) lecture courses and curriculum history",
+};
+
+export default function LecturesLayout({ children }: { children: React.ReactNode }) {
+  return <>{children}</>;
+}

refer_landing_page/app/lectures/page.tsx

@@ -1,16 +1,17 @@
-import React from "react";
-import type { Metadata } from "next";
+"use client";
+
+import React, { useEffect, useState } from "react";
 import { getSemesters } from "../../lib/api";
+import type { Semester } from "../../content/types";
 
-export const metadata: Metadata = {
-  title: "Lectures",
-  description: "AI Agent Networking Lab (ANL) lecture courses and curriculum history",
-};
+export default function LecturesPage() {
+  const [semesters, setSemesters] = useState<Semester[]>([]);
 
-export const dynamic = "force-dynamic";
-
-export default async function LecturesPage() {
-  const semesters = (await getSemesters()) ?? [];
+  useEffect(() => {
+    getSemesters().then((s) => {
+      if (s) setSemesters(s);
+    });
+  }, []);
 
   const recentSemesters = semesters.slice(0, 3);
   const olderSemesters = semesters.slice(3);