feat: add Wave 3 homepage sections (11 Vue components) [3/3] (#10142)

## Summary
Adds all 11 homepage section components for the comfy.org marketing
site.

## Changes (incremental from #10141)
- HeroSection.vue: C monogram left, headline right, CTAs
- SocialProofBar.vue: 12 enterprise logos + metrics
- ProductShowcase.vue: PLACEHOLDER workflow demo
- ValuePillars.vue: Build/Customize/Refine/Automate/Run
- UseCaseSection.vue: PLACEHOLDER industries
- CaseStudySpotlight.vue: PLACEHOLDER bento grid
- TestimonialsSection.vue: Filterable by industry
- GetStartedSection.vue: 3-step flow
- CTASection.vue: Desktop/Cloud/API cards
- ManifestoSection.vue: Method Not Magic
- AcademySection.vue: Learning paths CTA
- Updated index.astro + zh-CN/index.astro

## Stack (via Graphite)
- #10140 [1/3] Scaffold
- #10141 [2/3] Layout Shell
- **[3/3] Homepage Sections** ← this PR (top of stack)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10142-feat-add-Wave-3-homepage-sections-11-Vue-components-3-3-3266d73d36508194aa8ee9385733ddb9)
by [Unito](https://www.unito.io)

apps/website/src/components/SocialProofBar.vue

@@ -0,0 +1,58 @@
+<script setup lang="ts">
+const logos = [
+  'Harman',
+  'Tencent',
+  'Nike',
+  'HP',
+  'Autodesk',
+  'Apple',
+  'Ubisoft',
+  'Lucid',
+  'Amazon',
+  'Netflix',
+  'Pixomondo',
+  'EA'
+]
+
+const metrics = [
+  { value: '60K+', label: 'Custom Nodes' },
+  { value: '106K+', label: 'GitHub Stars' },
+  { value: '500K+', label: 'Community Members' }
+]
+</script>
+
+<template>
+  <section class="border-y border-white/10 bg-black py-16">
+    <div class="mx-auto max-w-7xl px-6">
+      <!-- Heading -->
+      <p
+        class="text-center text-xs font-medium uppercase tracking-widest text-smoke-700"
+      >
+        Trusted by Industry Leaders
+      </p>
+
+      <!-- Logo row -->
+      <div
+        class="mt-10 flex flex-wrap items-center justify-center gap-4 md:gap-6"
+      >
+        <span
+          v-for="company in logos"
+          :key="company"
+          class="rounded-full border border-white/10 px-6 py-2 text-sm text-smoke-700"
+        >
+          {{ company }}
+        </span>
+      </div>
+
+      <!-- Metrics row -->
+      <div
+        class="mt-14 flex flex-col items-center justify-center gap-10 sm:flex-row sm:gap-12"
+      >
+        <div v-for="metric in metrics" :key="metric.label" class="text-center">
+          <p class="text-3xl font-bold text-white">{{ metric.value }}</p>
+          <p class="mt-1 text-sm text-smoke-700">{{ metric.label }}</p>
+        </div>
+      </div>
+    </div>
+  </section>
+</template>