Fix Docker deployment and runtime environment variables

- Add --break-system-packages flag to pip install for Alpine Linux 3.12+ compatibility
- Configure Astro server to bind to 0.0.0.0 for Docker container accessibility
- Replace import.meta.env with process.env for runtime environment variable access in SSR
- Enable dynamic LOGIN configuration at runtime

Co-Authored-By: Warp <agent@warp.dev>

astro.config.mjs

@@ -12,6 +12,10 @@ export default defineConfig({
   adapter: node({
     mode: 'standalone'
   }),
+  server: {
+    host: '0.0.0.0',
+    port: 4321
+  },
   i18n: {
     defaultLocale: 'de',
     locales: ['de', 'en'],
@@ -20,4 +24,3 @@ export default defineConfig({
     }
   }
 });
-