Phase 01 — Single d6 roller

First iteration of the dice roller — a local, single-die interaction with no backend yet.

Added

• Next.js app scaffold (App Router, TypeScript, Tailwind v4, ESLint)
• Drop area displaying a single d6 face as an SVG pip sprite
• Roll button with a ~500ms random face-swap animation, settling on a Math.random() result
• Result popup shown in front of the Roll button; dismissible with any click, which re-enables the button

No persistence or multiplayer yet — purely local, client-side state. See CHANGELOG.md for details.