Implement Image Lazy Loading only single page I want work instantly

My site feels heavier than it should, and the waterfall chart confirms that static images are holding back the first render. I want every non-critical image to wait its turn so visitors get meaningful content instantly. The scope is simple yet precise: apply native or scripted lazy loading to all images across the site, maintain existing design integrity, and prove the performance gain with clear before-and-after metrics (PageSpeed Insights or similar).

Deliverables
• Audit of current image calls and sizes
• End-to-end lazy-loading implementation (HTML attribute or lightweight JS fallback for legacy browsers)
• Validation that CLS, LCP, and FCP all improve noticeably without visual glitches
• Short hand-off note so I can maintain the solution myself

No need to tackle compression or WebP right now; this task is strictly about deferring image downloads until they enter the viewport.