Initial fullstack project setup with Next.js 15, Gin, PostgreSQL and Docker Compose

- Frontend: Next.js 15 (App Router), Auth.js v5, shadcn/ui, MagicUI
- Backend: Go + Gin + GORM with layered architecture
- Auth: Local credentials login with optional Keycloak OAuth binding
- Admin: RBAC user management for admin role
- Dev: Docker Compose with hot reload for both frontend and backend
- Docker: 3-service orchestration (frontend, backend, postgres)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/app/(main)/layout.tsx

@@ -0,0 +1,46 @@
+import Link from "next/link";
+import { auth } from "@/auth";
+import { Button } from "@/components/ui/button";
+import { signOut } from "@/auth";
+
+export default async function MainLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  const session = await auth();
+  const user = session?.user as any;
+
+  return (
+    <div className="min-h-screen bg-gray-50">
+      <header className="border-b bg-white">
+        <div className="mx-auto flex max-w-6xl items-center justify-between px-4 py-3">
+          <Link href="/" className="text-lg font-bold">
+            EvanPage
+          </Link>
+          <nav className="flex items-center gap-4">
+            <Link href="/dashboard" className="text-sm hover:underline">
+              仪表盘
+            </Link>
+            {user?.role === "admin" && (
+              <Link href="/admin" className="text-sm hover:underline">
+                管理后台
+              </Link>
+            )}
+            <form
+              action={async () => {
+                "use server";
+                await signOut({ redirectTo: "/login" });
+              }}
+            >
+              <Button variant="ghost" size="sm" type="submit">
+                退出
+              </Button>
+            </form>
+          </nav>
+        </div>
+      </header>
+      <main className="mx-auto max-w-6xl px-4 py-6">{children}</main>
+    </div>
+  );
+}