store workflow start block code (#3283)

skyvern/config.py

@@ -347,6 +347,9 @@ class Settings(BaseSettings):
     ENCRYPTOR_AES_SALT: str | None = None
     ENCRYPTOR_AES_IV: str | None = None
 
+    # script generation settings
+    WORKFLOW_START_BLOCK_LABEL: str = "__start_block__"
+
     def get_model_name_to_llm_key(self) -> dict[str, dict[str, str]]:
         """
         Keys are model names available to blocks in the frontend. These map to key names