feat: add full Reputation Blueprint demo page at /report-demo

Port the engine's report renderer (37 component files) into the marketing
site with anonymized data from a real 596-review analysis. Visitors see
the exact multi-page report paying customers receive — cover, executive
summary, rating dashboard, theme analysis, domain performance, trends,
critical issues, strengths, action plan, and tracking framework.

- Anonymized business data (Bistro El Sol, score 83.3)
- EN/ES language toggle in report toolbar
- Recharts: gauge, radar, scatter, donut, trend, heatmap charts
- Sticky CTA bar converting demo viewers to customers
- Demo nav link updated from anchor to /report-demo route

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/i18n/src/translations/en/marketing.json

@@ -1,5 +1,9 @@
 {
   "demoLabel": "Demo",
+  "demoPage": {
+    "ctaText": "Like what you see? Get yours",
+    "ctaButton": "Get your Blueprint"
+  },
   "product": {
     "title": "See exactly what's driving your Google rating",
     "description": "WhyRating analyzes every review and shows you what customers love, what frustrates them, and what to fix first. Enterprise-grade insights. Small business price. No subscription."

packages/i18n/src/translations/es/marketing.json

@@ -1,5 +1,9 @@
 {
   "demoLabel": "Demo",
+  "demoPage": {
+    "ctaText": "¿Te gusta lo que ves? Obtén el tuyo",
+    "ctaButton": "Obtén tu Radiografía"
+  },
   "product": {
     "title": "Descubre qué está impulsando tu calificación en Google",
     "description": "WhyRating analiza cada reseña y te muestra qué les encanta a tus clientes, qué les frustra y qué deberías corregir primero. Análisis de nivel empresarial. Precio para pequeños negocios. Sin suscripción."