fix: improve platform homepage pricing UI and restore footer links

- Fix toggle button alignment with consistent min-widths
- Add € currency signs to all prices
- Show all tier features with greyed unavailable ones
- Add multi-channel integration feature for Enterprise tier
- Change Contact Sales to mailto link (fixes 404)
- Restore footer CMS page links (About, FAQ, Contact)
- Add footer link translations for all 4 languages

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/locales/de.json

@@ -512,6 +512,7 @@
       "eu_vat_invoicing": "EU-MwSt-Rechnungen",
       "analytics_dashboard": "Analyse-Dashboard",
       "api_access": "API-Zugang",
+      "multi_channel": "Multi-Channel-Integration",
       "products": "Produkte",
       "team_member": "Teammitglied",
       "unlimited": "Unbegrenzt",
@@ -631,7 +632,10 @@
       "contact": "Kontakt",
       "copyright": "© {year} Wizamart. Entwickelt für den luxemburgischen E-Commerce.",
       "privacy": "Datenschutzerklärung",
-      "terms": "Nutzungsbedingungen"
+      "terms": "Nutzungsbedingungen",
+      "about": "Über uns",
+      "faq": "FAQ",
+      "contact_us": "Kontaktieren Sie uns"
     },
     "modern": {
       "badge_integration": "Offizielle Integration",