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+# HTTP port (default: 3000)
+PORT=3000
+
+# Firebase Admin: inline service account JSON (one line).
+# If unset, uses Application Default Credentials (e.g. GOOGLE_APPLICATION_CREDENTIALS).
+# FIREBASE_SERVICE_ACCOUNT_JSON={"type":"service_account",...}
+
+# Local persistence directory for registered FCM tokens (default: ./data)
+# FCM_TOKEN_DATA_DIR=./data
+
+# Set to "test-local" to bypass ethr JWT expiry verification in local dev only.
+# NODE_ENV=test-local