Fix all TypeScript errors; remove unused element/magicui components

- Add missing deps: @base-ui/react, react-hook-form, next-themes, react-is
- Bump recharts to 3.9.1 and update chart.tsx to the recharts v3-compatible
  shadcn version
- Pin react-resizable-panels to v3 (v4 renamed the PanelGroup exports)
- Add showCloseButton prop to DialogContent (used by CommandDialog)
- Replace custom cn with standard clsx + twMerge (fixes Base UI className
  types and object-syntax classes being dropped at runtime)
- Clean up tsconfig (drop dead Vite project references; Next.js updated
  moduleResolution/jsx during build)
- Remove unused components/elements and components/magicui, drop bun.lock
  in favor of yarn.lock, simplify app/page.tsx

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019bE5ox6WnAPgqRgkx3pLCu

.gitignore

@@ -5,3 +5,4 @@
 node_modules/*
 next-env.d.ts
 .DS_Store
+*.tsbuildinfo