feat: add stage 0 foundation

frontend/tailwind.config.ts

@@ -0,0 +1,37 @@
+import type { Config } from 'tailwindcss'
+
+const config: Config = {
+  darkMode: ['class'],
+  content: ['./index.html', './src/**/*.{ts,tsx}'],
+  theme: {
+    extend: {
+      colors: {
+        border: 'hsl(var(--border))',
+        background: 'hsl(var(--background))',
+        foreground: 'hsl(var(--foreground))',
+        muted: {
+          DEFAULT: 'hsl(var(--muted))',
+          foreground: 'hsl(var(--muted-foreground))'
+        },
+        surface: 'hsl(var(--surface))',
+        primary: {
+          DEFAULT: 'hsl(var(--primary))',
+          foreground: 'hsl(var(--primary-foreground))'
+        },
+        success: 'hsl(var(--success))',
+        warning: 'hsl(var(--warning))',
+        danger: 'hsl(var(--danger))',
+        info: 'hsl(var(--info))',
+        ai: 'hsl(var(--ai-accent))'
+      },
+      borderRadius: {
+        lg: 'var(--radius)',
+        md: 'calc(var(--radius) - 2px)',
+        sm: 'calc(var(--radius) - 4px)'
+      }
+    }
+  },
+  plugins: [require('tailwindcss-animate')]
+}
+
+export default config