feat: add solutions list/detail pages

- types: SolutionPageSummary/Detail
- services/solution.service.ts
- app/solutions: list + detail pages
- Header nav: add 解决方案 link

app/solutions/[slug]/page.tsx

@@ -0,0 +1,39 @@
+import { notFound } from "next/navigation";
+import type { Metadata } from "next";
+import { getSolutionBySlug } from "@/services/solution.service";
+import { BlockRenderer } from "@/blocks/BlockRenderer";
+
+interface SolutionDetailPageProps {
+  params: Promise<{ slug: string }>;
+}
+
+export async function generateMetadata({
+  params,
+}: SolutionDetailPageProps): Promise<Metadata> {
+  const { slug } = await params;
+  const solution = await getSolutionBySlug(slug).catch(() => null);
+  return { title: solution?.title ?? "解决方案未找到" };
+}
+
+export default async function SolutionDetailPage({
+  params,
+}: SolutionDetailPageProps) {
+  const { slug } = await params;
+  const solution = await getSolutionBySlug(slug).catch(() => null);
+
+  if (!solution) {
+    notFound();
+  }
+
+  return (
+    <article className="mx-auto max-w-3xl px-6 py-24">
+      <h1 className="mb-2 text-4xl font-bold text-slate-900">
+        {solution.title}
+      </h1>
+      {solution.industry && (
+        <p className="mb-12 text-sm text-slate-500">{solution.industry}</p>
+      )}
+      <BlockRenderer blocks={solution.body} />
+    </article>
+  );
+}

app/solutions/page.tsx

@@ -0,0 +1,38 @@
+import Link from "next/link";
+import type { Metadata } from "next";
+import { getSolutionList } from "@/services/solution.service";
+
+export const metadata: Metadata = {
+  title: "解决方案",
+};
+
+export default async function SolutionListPage() {
+  const solutions = await getSolutionList().catch(() => []);
+
+  return (
+    <div className="mx-auto max-w-4xl px-6 py-24">
+      <h1 className="mb-12 text-4xl font-bold text-slate-900">解决方案</h1>
+      <ul className="space-y-6">
+        {solutions.map((solution) => (
+          <li key={solution.id} className="border-b border-slate-100 pb-6">
+            <Link
+              href={`/solutions/${solution.meta.slug}`}
+              className="text-2xl font-semibold text-slate-900 hover:text-primary"
+            >
+              {solution.title}
+            </Link>
+            {solution.industry && (
+              <p className="mt-1 text-sm text-slate-500">{solution.industry}</p>
+            )}
+            {solution.summary && (
+              <p className="mt-2 text-slate-600">{solution.summary}</p>
+            )}
+          </li>
+        ))}
+        {solutions.length === 0 && (
+          <p className="text-slate-500">暂无解决方案，或后端服务未连接。</p>
+        )}
+      </ul>
+    </div>
+  );
+}