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>

postcss.config.mjs

@@ -0,0 +1,8 @@
+/** @type {import('postcss-load-config').Config} */
+const config = {
+  plugins: {
+    '@tailwindcss/postcss': {},
+  },
+}
+
+export default config