refactor: flatten monorepo to single web package (#12)

Flatten the pnpm monorepo (apps/web + packages/*) into a single web package at the repo root.

- Move app/lib/components/scripts/public to root; drop apps/web and packages/* wrappers
- Rewrite tsconfig paths (@infiplot/*) to ./lib/*; turbopack.root = __dirname
- Update Vercel (no root-directory) and Cloudflare (pnpm build:cf at root) deploy paths
- Regenerate pnpm-lock.yaml to drop stale workspace importers
- Bump engines.node to >=22 to match wrangler

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

components/PresetCard.tsx

@@ -0,0 +1,38 @@
+"use client";
+
+import { useRouter } from "next/navigation";
+import type { Preset } from "@/lib/presets";
+
+export function PresetCard({
+  preset,
+  ordinal,
+}: {
+  preset: Preset;
+  ordinal: string;
+}) {
+  const router = useRouter();
+  return (
+    <button
+      onClick={() => router.push(`/play?preset=${preset.id}`)}
+      className="group block w-full py-10 md:py-12 border-t border-clay-900/10 hover:border-clay-900/35 transition-[border-color,padding] duration-500 text-left"
+    >
+      <div className="flex items-baseline gap-6 md:gap-10">
+        <span className="font-serif italic text-2xl md:text-3xl text-clay-400 group-hover:text-clay-700 transition-colors duration-500 w-8 shrink-0">
+          {ordinal}
+        </span>
+        <div className="flex-1 min-w-0">
+          <h3 className="font-serif text-3xl md:text-4xl text-clay-900 leading-tight mb-2.5">
+            {preset.title}
+          </h3>
+          <p className="text-sm text-clay-600 leading-relaxed max-w-md">
+            {preset.blurb}
+          </p>
+        </div>
+        <span className="hidden md:flex items-center gap-3 text-[10px] tracking-[0.4em] text-clay-400 group-hover:text-ember-500 transition-colors duration-500 shrink-0 self-center">
+          ENTER
+          <span className="w-7 h-px bg-current transition-all duration-500 group-hover:w-12" />
+        </span>
+      </div>
+    </button>
+  );
+}