feat: Migrate frontend from static HTML to Next.js 16 App Router

feat: Migrate frontend from static HTML to Next.js 16 App Router

feat: Google-style top bar + smart FAB visibility

fix: no transition on reload + AI search fix + skeletons everywhere + hide search btn

feat: true iOS-style navigation stack with parallax

fix: show products immediately (setLoading false after products, not after AI)

fix: restore fast search (Promise.all parallel) + playable skeleton loader (draggable C + cards)

fix: search shows products immediately (AI loads in background) + more dramatic page transitions

feat: pure white design (no cyan) + AI-powered search + animations + page transitions + skeleton loaders

fix: close results area div before follow-up bar

feat: conversational AI mode search (Alibaba-style) with thought process toggle, embedded product grid, follow-up chat

feat: Migrate frontend from static HTML to Next.js 16 App Router

feat: Migrate frontend from static HTML to Next.js 16 App Router

fix: Flatten nested src/src/ and public/public/, remove invalid eslint config key