Cache: fix 1-year CSS cache and add version busting

- .htaccess: remove duplicate cache block that set all CSS/JS to max-age=31536000
  CSS/JS now use max-age=3600 must-revalidate (was 1 year, breaking live edits)
- index.php: bump main.min.css version v1.1.3 -> v1.1.4
- All 78 PHP files: add ?v=20260222 to main.css and cro-enhancements.css refs
  Forces browser cache bust for all pages after todays accessibility changes

blog/articles/gdpr-data-minimisation-practices.php

@@ -33,7 +33,7 @@ $read_time = 6;
     <meta name="article:tag" content="GDPR, Data Protection, Compliance, Privacy">
     
     <!-- Preload critical resources -->
-    <link rel="preload" href="../../assets/css/main.css" as="style">
+    <link rel="preload" href="../../assets/css/main.css?v=20260222" as="style">
     <link rel="preload" href="../../assets/images/ukds-main-logo.png" as="image">
     
     <!-- Open Graph / Social Media -->
@@ -59,8 +59,8 @@ $read_time = 6;
     <link href="https://fonts.googleapis.com/css2?family=Roboto+Slab:wght@300;400;500;600;700&family=Lato:wght@300;400;500;600;700&display=swap" rel="stylesheet">
     
     <!-- Styles -->
-    <link rel="stylesheet" href="../../assets/css/main.css">
-    <link rel="stylesheet" href="../../assets/css/cro-enhancements.css">
+    <link rel="stylesheet" href="../../assets/css/main.css?v=20260222">
+    <link rel="stylesheet" href="../../assets/css/cro-enhancements.css?v=20260222">
     
     <!-- Article Schema -->
     <script type="application/ld+json">