feat: complete agency site build (Phases 1-7)

Full Next.js 16 + Payload CMS 3.x agency site with:
- Homepage: Hero, TrustBar, Services, Configurator wizard, Process,
  Selected Works, Philosophy, CTA Banner
- Sub-pages: /services (3 pillars + AI Layer), /work/[slug] (case
  studies), /about (philosophy + story)
- Configurator: 3-step wizard with AI brief generation API
- i18n: Full EN/FR bilingual with next-intl
- Design system: Cormorant Garamond + Inter, celestial blue palette,
  glassmorphism nav, Framer Motion animations
- Payload CMS collections: Projects, Services, Submissions, Media

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

next.config.mjs

@@ -0,0 +1,14 @@
+import { withPayload } from '@payloadcms/next/withPayload'
+import createNextIntlPlugin from 'next-intl/plugin'
+
+const withNextIntl = createNextIntlPlugin('./src/i18n/request.ts')
+
+/** @type {import('next').NextConfig} */
+const nextConfig = {
+  output: 'standalone',
+  images: {
+    formats: ['image/avif', 'image/webp'],
+  },
+}
+
+export default withPayload(withNextIntl(nextConfig))