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>

blog/articles/competitor-price-monitoring-software-build-vs-buy-analysis.php

@@ -1318,6 +1318,8 @@ $modified_date = "2025-08-08";
         </article>
 
         <!-- Related Articles -->
+        <?php include $_SERVER['DOCUMENT_ROOT'] . '/includes/author-bio.php'; ?>
+
         <?php include '../../includes/article-footer.php'; ?>
     </main>