feat(website): add zh-CN translations for homepage and secondary pages (#10157)

## Summary

<!-- One sentence describing what changed and why. -->

## Changes

- **What**: <!-- Core functionality added/modified -->
- **Breaking**: <!-- Any breaking changes (if none, remove this line)
-->
- **Dependencies**: <!-- New dependencies (if none, remove this line)
-->

## Review Focus

<!-- Critical design decisions or edge cases that need attention -->

<!-- If this PR fixes an issue, uncomment and update the line below -->
<!-- Fixes #ISSUE_NUMBER -->

## Screenshots (if applicable)

<!-- Add screenshots or video recording to help explain your changes -->

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10157-feat-website-add-zh-CN-translations-for-homepage-and-secondary-pages-3266d73d3650811f918cc35eca62a4bc)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>

apps/website/src/components/UseCaseSection.vue

@@ -1,14 +1,18 @@
 <!-- TODO: Wire category content swap when final assets arrive -->
 <script setup lang="ts">
-import { ref } from 'vue'
+import { computed, ref } from 'vue'
+import type { Locale } from '../i18n/translations'
+import { t } from '../i18n/translations'
 
-const categories = [
-  'VFX & Animation',
-  'Creative Agencies',
-  'Gaming',
-  'eCommerce & Fashion',
-  'Community & Hobbyists'
-]
+const { locale = 'en' } = defineProps<{ locale?: Locale }>()
+
+const categories = computed(() => [
+  t('useCase.vfx', locale),
+  t('useCase.agencies', locale),
+  t('useCase.gaming', locale),
+  t('useCase.ecommerce', locale),
+  t('useCase.community', locale)
+])
 
 const activeCategory = ref(0)
 </script>
@@ -27,7 +31,7 @@ const activeCategory = ref(0)
         <!-- Center content -->
         <div class="flex flex-col items-center text-center lg:flex-[2]">
           <h2 class="text-3xl font-bold text-white">
-            Built for Every Creative Industry
+            {{ t('useCase.heading', locale) }}
           </h2>
 
           <nav
@@ -52,15 +56,14 @@ const activeCategory = ref(0)
           </nav>
 
           <p class="mt-10 max-w-lg text-smoke-700">
-            Powered by 60,000+ nodes, thousands of workflows, and a community
-            that builds faster than any one company could.
+            {{ t('useCase.body', locale) }}
           </p>
 
           <a
             href="/workflows"
             class="mt-8 rounded-full border border-brand-yellow px-8 py-3 text-sm font-semibold text-brand-yellow transition-colors hover:bg-brand-yellow hover:text-black"
           >
-            EXPLORE WORKFLOWS
+            {{ t('useCase.cta', locale) }}
           </a>
         </div>