fix(seo): Remove technical jargon and add SEO meta tags

- Replace "multi-tenant" wording with user-friendly alternatives
  - Hero subheadline: "Secure" instead of "Multi-tenant"
  - Feature title: "Enterprise Security" instead of "Multi-Tenant Architecture"
  - Updated testimonials and FAQ to remove technical references
- Add comprehensive SEO meta tags to index.html:
  - Meta description for search engines
  - Open Graph tags for social sharing
  - Twitter card meta tags
  - Canonical URL and robots directives
- Update all language files (en, es, fr, de) with consistent changes

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

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

frontend/index.html

@@ -5,7 +5,27 @@
     <link rel="icon" type="image/svg+xml" href="/vite.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <!-- CSP: Disabled in development due to browser extension conflicts. Enable in production via server headers. -->
-    <title>Smooth Schedule - Multi-Tenant Scheduling</title>
+    <title>Smooth Schedule | Online Appointment Scheduling Software</title>
+    <meta name="description" content="The all-in-one scheduling platform for service businesses. Manage appointments, staff, and payments effortlessly. Start free today." />
+
+    <!-- Open Graph / Facebook -->
+    <meta property="og:type" content="website" />
+    <meta property="og:title" content="Smooth Schedule | Online Appointment Scheduling Software" />
+    <meta property="og:description" content="The all-in-one scheduling platform for service businesses. Manage appointments, staff, and payments effortlessly." />
+    <meta property="og:image" content="https://smoothschedule.com/og-image.png" />
+    <meta property="og:url" content="https://smoothschedule.com" />
+    <meta property="og:site_name" content="Smooth Schedule" />
+
+    <!-- Twitter -->
+    <meta name="twitter:card" content="summary_large_image" />
+    <meta name="twitter:title" content="Smooth Schedule | Online Appointment Scheduling Software" />
+    <meta name="twitter:description" content="The all-in-one scheduling platform for service businesses. Manage appointments, staff, and payments effortlessly." />
+    <meta name="twitter:image" content="https://smoothschedule.com/og-image.png" />
+
+    <!-- Additional SEO -->
+    <meta name="robots" content="index, follow" />
+    <meta name="author" content="Smooth Schedule Inc." />
+    <link rel="canonical" href="https://smoothschedule.com" />
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
     <style>
       /* Ensure full height for the app */