feat: add Gen 1 maintenance mode deprecation warning to CLI

Author: Simone319

packages/amplify-cli/src/index.ts

@@ -63,6 +63,13 @@ const disableCDKDeprecationWarning = () => {
  * Command line entry point
  */
 export const run = async (startTime: number): Promise<void> => {
+  // Gen 1 CLI deprecation warning — prints to stderr to avoid interfering with JSON/stdout parsing
+  process.stderr.write(
+    '\n\x1b[33m⚠️  WARNING: AWS Amplify Gen 1 CLI is in maintenance mode and will reach end of life on May 1, 2027.\n' +
+      'During maintenance mode, only critical bug fixes and security patches will be provided.\n' +
+      'Migrate to Amplify Gen 2: https://docs.amplify.aws/react/start/migrate-to-gen2/\x1b[0m\n\n',
+  );
+
   deleteOldVersion();
 
   //TODO: This is a temporary suppression for CDK deprecation warnings, which should be removed after the migration is complete