feat: 补全剩余 6 个 StreamField Block 前端渲染 (ProductCard/Pricing/Timeline/Team/TechStack/Video)

- types/wagtail.ts 新增对应 6 个 Block 值类型接口及 StreamFieldBlock 联合类型分支
- 新建 6 个渲染组件：ProductCardGrid/Pricing/Timeline/Team/TechStack/Video，风格与既有 Block 一致
- BlockRenderer.tsx 映射表接入新组件，key 与后端 COMMON_BLOCKS 保持一致
- lint/build 均验证通过

blocks/tech-stack/TechStack.tsx

@@ -0,0 +1,28 @@
+import type { TechStackBlockValue } from "@/types/wagtail";
+
+export default function TechStack({ value }: { value: TechStackBlockValue }) {
+  return (
+    <section className="bg-slate-50 py-24">
+      <div className="mx-auto max-w-6xl px-6">
+        {value.heading && (
+          <h2 className="mb-16 text-center text-4xl font-bold text-slate-900">
+            {value.heading}
+          </h2>
+        )}
+        <div className="grid grid-cols-2 gap-6 sm:grid-cols-3 lg:grid-cols-4">
+          {value.items?.map((item, index) => (
+            <div
+              key={`${item.label}-${index}`}
+              className="flex flex-col items-center gap-3 rounded-2xl bg-white p-6 text-center shadow-sm"
+            >
+              {item.icon && <span className="text-3xl">{item.icon}</span>}
+              <span className="text-sm font-medium text-slate-700">
+                {item.label}
+              </span>
+            </div>
+          ))}
+        </div>
+      </div>
+    </section>
+  );
+}