Comprehensive SEO and UI improvements across site

SEO Improvements:
- Add Twitter/OG meta tags to gdpr-compliance.php and terms-of-service.php
- Add author bios with E-E-A-T signals to all blog articles
- Add breadcrumb schema markup to key pages
- Create new service pages: price-monitoring.php, competitive-intelligence.php
- Create location pages: london.php, manchester.php, birmingham.php
- Update sitemap.xml with new pages

UI/CSS Improvements:
- Move testimonials section from inline styles to CSS classes
- Standardize hero gradients to #144784 → #179e83 across all pages
- Unify card border styles to border-left: 4px solid #179e83
- Fix CTA gradient direction consistency on location pages
- Standardize breadcrumb colors to #144784
- Replace all purple accent colors (#667eea, #764ba2) with brand colors
- Add CSS variables for brand consistency in main.css

Code Cleanup:
- Delete 6 emergency CSS fix files (button-emergency-fix.css, etc.)
- Remove related-articles-fix.css references from blog articles
- Consolidate styles into main.css

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

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

gdpr-compliance.php

@@ -21,7 +21,22 @@ $canonical_url = "https://ukdataservices.co.uk/gdpr-compliance";
     <meta name="author" content="UK Data Services">
     <meta name="robots" content="index, follow">
     <link rel="canonical" href="<?php echo htmlspecialchars($canonical_url); ?>">
-    
+
+    <!-- Open Graph / Facebook -->
+    <meta property="og:type" content="website">
+    <meta property="og:url" content="<?php echo htmlspecialchars($canonical_url); ?>">
+    <meta property="og:title" content="<?php echo htmlspecialchars($page_title); ?>">
+    <meta property="og:description" content="<?php echo htmlspecialchars($page_description); ?>">
+    <meta property="og:image" content="https://ukdataservices.co.uk/assets/images/ukds-og-image.png">
+    <meta property="og:site_name" content="UK Data Services">
+
+    <!-- Twitter -->
+    <meta name="twitter:card" content="summary_large_image">
+    <meta name="twitter:url" content="<?php echo htmlspecialchars($canonical_url); ?>">
+    <meta name="twitter:title" content="<?php echo htmlspecialchars($page_title); ?>">
+    <meta name="twitter:description" content="<?php echo htmlspecialchars($page_description); ?>">
+    <meta name="twitter:image" content="https://ukdataservices.co.uk/assets/images/ukds-og-image.png">
+
     <!-- Favicon -->
     <link rel="icon" type="image/svg+xml" href="assets/images/favicon.svg">
     <link rel="preconnect" href="https://fonts.googleapis.com">