init: add source code from src.zip

src/constants/keys.ts

@@ -0,0 +1,11 @@
+import { isEnvTruthy } from '../utils/envUtils.js'
+
+// Lazy read so ENABLE_GROWTHBOOK_DEV from globalSettings.env (applied after
+// module load) is picked up. USER_TYPE is a build-time define so it's safe.
+export function getGrowthBookClientKey(): string {
+  return process.env.USER_TYPE === 'ant'
+    ? isEnvTruthy(process.env.ENABLE_GROWTHBOOK_DEV)
+      ? 'sdk-yZQvlplybuXjYh6L'
+      : 'sdk-xRVcrliHIlrg4og4'
+    : 'sdk-zAZezfDKGoZuXXKe'
+}