feat: Upgrade to Astro with full PDPA compliance

PDPA Features:
✅ Cookie consent banner
✅ Consent logging API
✅ Admin dashboard
✅ Privacy Policy
✅ Terms & Conditions

Technical:
✅ Astro 5.x + Tailwind v4
✅ Docker on port 80
✅ SQLite database
✅ 15 pages built

Ready for Easypanel deployment.

astro.config.mjs

@@ -0,0 +1,11 @@
+// @ts-check
+import { defineConfig } from 'astro/config';
+
+import tailwindcss from '@tailwindcss/vite';
+
+// https://astro.build/config
+export default defineConfig({
+  vite: {
+    plugins: [tailwindcss()]
+  }
+});