[codex] Make loop search more prominent

[mberman84]

What changed

• adds a visible high-contrast “Search the library” label
• gives the search input a bordered 52px field, larger icon, and clearer prompt
• adds hover/focus treatments and keeps the control responsive
• cache-busts the homepage stylesheet and adds regression assertions

Why

The previous transparent, unlabeled search treatment blended into the surrounding controls and was easy to overlook.

Validation

• node --check site/script.js
• node scripts/check.mjs
• npm --prefix worker run check (41 tests)
• JSON validation for here.now data/proxy and SEO benchmark files
• git diff --check
• rendered desktop and 390px mobile browser verification