Add an image gallery with a lightbox to {{page_or_feature}} in my {{tech_stack}} project. Read the existing code first, prefer the browser's native dialog or a small library over a heavy one, and show me a short plan before changing files. The grid: - Images come from one list or table with the file, alt text, caption and category, and alt text is required - Responsive sizes and modern formats, width and height set to prevent layout shift, and lazy-loading below the fold - A soft placeholder color while each image loads - Optional category filters as real buttons The lightbox: - Opens as a modal dialog labeled by the caption; focus moves in, stays inside, and returns to the thumbnail on close - Escape closes it; arrow keys and on-screen buttons move between images, and swiping works on touch screens - A counter such as 4 of 20, with the caption shown under each image - Pinch-to-zoom stays enabled on phones - The next and previous images preload - Each image has its own shareable link, and the back button closes the lightbox - Animations switch off when the visitor prefers reduced motion - Buttons at least 44px, and WCAG 2.2 AA throughout When you're done, list the files changed, how to add new photos, and anything you assumed.