Site improvements: nav refactor, CSS readability, hover fixes, remove unverified badges

- Refactored navigation: all 44 pages now use shared includes/nav.php
- Added Free Tools link to navigation (was missing from 29+ pages)
- CSS readability: darker body text (#333), secondary text (#555), bolder hero subtitle
- CSS: darkened link colour (#148a72) for WCAG AA compliance
- CSS: increased stat label font size to 1rem
- Fixed industry-card hover white-on-white text bug
- Removed ICO Registered and Cyber Essentials claims (not yet registered)
- Cache version bumped to v1.1.2

blog/categories/case-studies.php

@@ -75,29 +75,7 @@ $og_image = "https://ukdataservices.co.uk/assets/images/blog/case-studies-catego
     <a href="#main-content" class="skip-to-content">Skip to main content</a>
     
     <!-- Navigation -->
-    <nav class="navbar" id="navbar">
-        <div class="nav-container">
-            <div class="nav-logo">
-                <a href="../../">
-                    <img src="../../assets/images/ukds-main-logo.png" alt="UK Data Services" class="logo" loading="eager">
-                </a>
-            </div>
-            <div class="nav-menu" id="nav-menu">
-                <a href="../../" class="nav-link">Home</a>
-                <a href="../../#services" class="nav-link">Capabilities</a>
-                <a href="../../project-types.php" class="nav-link">Project Types</a>
-                <a href="../../about.php" class="nav-link">About</a>
-                <a href="../" class="nav-link active">Blog</a>
-                <a href="../../#contact" class="nav-link">Contact</a>
-                <a href="../../quote.php" class="nav-link cta-button">Request Consultation</a>
-            </div>
-            <div class="nav-toggle" id="nav-toggle">
-                <span class="bar"></span>
-                <span class="bar"></span>
-                <span class="bar"></span>
-            </div>
-        </div>
-    </nav>
+    <?php include($_SERVER["DOCUMENT_ROOT"] . "/includes/nav.php"); ?>
 
     <!-- Breadcrumb Navigation -->
     <div class="breadcrumb">