Initial commit: full-stack Bun + Elysia + React template

Elysia.js API with session-based auth (email/password + Google OAuth),
role system (USER/ADMIN/SUPER_ADMIN), Prisma + PostgreSQL, React 19
with Mantine UI, TanStack Router, dark theme, and comprehensive test
suite (unit, integration, E2E with Lightpanda).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

postcss.config.js

@@ -0,0 +1,14 @@
+export default {
+  plugins: {
+    'postcss-preset-mantine': {},
+    'postcss-simple-vars': {
+      variables: {
+        'mantine-breakpoint-xs': '36em',
+        'mantine-breakpoint-sm': '48em',
+        'mantine-breakpoint-md': '62em',
+        'mantine-breakpoint-lg': '75em',
+        'mantine-breakpoint-xl': '88em',
+      },
+    },
+  },
+}