feat(01-01): scaffold Vite project with CSS design system and project structure

- Vite 6 + TypeScript + Biome + Vitest configured
- All directories from spec section 13 created
- CSS custom properties for full color palette and finger colors
- index.html with 5 screen sections and Google Fonts
- Dev server binds to 0.0.0.0:5173 for VPS access

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

vite.config.ts

@@ -0,0 +1,6 @@
+import { defineConfig } from "vite";
+
+export default defineConfig({
+	server: { host: "0.0.0.0", port: 5173 },
+	preview: { host: "0.0.0.0", port: 4173 },
+});