SEO: fix 404 redirects, sitemap cleanup, canonical fix, internal links

- .htaccess: 301 redirect data-analytics-companies-london-top-providers → -compared
- .htaccess: 301 redirect gdpr-compliance-web-scraping-uk-guide → web-scraping-compliance-uk-guide
- sitemap.xml: remove redirecting /services/data-analytics entry
- sitemap.xml: remove duplicate real-time-analytics-streaming (2025) entry
- sitemap.xml: add locations/london, /manchester, /birmingham pages
- real-time-analytics-streaming.php: canonical → real-time-analytics-streaming-data (2026 version)
- data-analytics-companies-london-top-providers-compared.php: internal link to churn article
- python-data-pipeline-tools-2025.php: internal link to churn article
- real-time-analytics-streaming-data.php: internal link to churn article

blog/articles/data-analytics-companies-london-top-providers-compared.php

@@ -827,7 +827,7 @@ $modified_date = "2025-08-08";
 
                         <div class="faq-item">
                             <h3>How long do typical analytics projects take?</h3>
-                            <p>Project timelines vary significantly: analytics strategy (4-12 weeks), BI implementations (3-9 months), predictive analytics (2-6 months), and full data platform builds (6-18 months). Agile approaches typically deliver value in 2-4 week sprints.</p>
+                            <p>Project timelines vary significantly: analytics strategy (4-12 weeks), BI implementations (3-9 months), predictive analytics (2-6 months), and full data platform builds (6-18 months). Agile approaches typically deliver value in 2-4 week sprints. For a deeper look at predictive timelines in practice, see our guide on <a href="/blog/articles/predictive-analytics-customer-churn">predictive analytics for customer churn reduction</a>.</p>
                         </div>
 
                         <div class="faq-item">