day 3 - Final Polish & Refactoring

• massive code cleanup: broke down a monolithic main.js into clean modules (clock.js, apod.js, bookmarks.js, search.js soon)
• fixed UI visibility issue where search results background obscured the NASA image
• fixed z-index bug to ensure the APOD description info panel is fully readable while searching
• built custom bookmarks functionality: users can now dynamically add and remove their own links that persist via localStorage (goodbye hardcoded links)
• implemented zero-delay background rendering: app now instantly loads a cached background on initial load while fetching the fresh NASA API image in the background, eliminating any black screen delays
• project is officially ready to ship! 🚀