Reading Library V4.3.9 — Viewer and resource-panel refinement

Changes in this release
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• Added Zoom Out, Zoom In and Fit controls to the regional Reading Text PDF viewer.
• Zoom supports 75%, 100%, 125%, 150%, 175% and 200% while retaining UK/US page isolation.
• Removed the underlying PowerPoint source filename from the Presentation panel.
• Restyled Resource Materials cards with clearer descriptions, stronger visual hierarchy, premium borders, shadows and hover states.
• Restyled PowerPoint / Google Slides presentation options as premium teaching cards with format badges.
• Retains the V4.3.8 Reading Framework, Discover search placement, hidden resource filenames, regional page repair and UK/US localisation fixes.
