fix: Add nixpacks configuration for Astro deployment

dealplustech-astro/node_modules/astro/dist/cli/domain/command.d.ts

@@ -0,0 +1,8 @@
+import type { HelpPayload } from './help-payload.js';
+interface Command<T extends (...args: Array<any>) => any> {
+    help: HelpPayload;
+    run: T;
+}
+export type AnyCommand = Command<(...args: Array<any>) => any>;
+export declare function defineCommand<T extends AnyCommand>(command: T): T;
+export {};