ui: hide generated code in logs by default via NATURALCAD_SHOW_CODE flag

apps/gradio-demo/README.md

@@ -65,6 +65,7 @@ Optional environment variables:
 - `NATURALCAD_BACKEND_URL` (leave unset for a pure Space-only MVP, or set it to enable backend-assisted spec generation + artifact upload)
 - `NATURALCAD_API_KEY`
 - `NATURALCAD_BACKEND_TIMEOUT` (default `4` seconds)
+- `NATURALCAD_SHOW_CODE` (default `false`; set `true` to show generated build123d code in UI logs)
 - `BUILD123D_PYTHON` (defaults to the current Python runtime, which is better for Hugging Face Space deployment)
 
 When backend is enabled and returns a `job.id`, the app will POST STL/STEP files to:
@@ -75,4 +76,4 @@ Runtime artifacts:
 - archived runs in `artifacts/runs/` (GLB preview is ephemeral and regenerated locally)
 - lightweight run logs in `artifacts/logs/runs.jsonl`
 
-Open http://localhost:7860
+Open http://localhost:7860

apps/gradio-demo/app/main.py

@@ -24,6 +24,7 @@ BUILD123D_PYTHON = os.getenv("BUILD123D_PYTHON", sys.executable)
 BACKEND_URL = os.getenv("NATURALCAD_BACKEND_URL", os.getenv("NL_CAD_BACKEND_URL", "")).strip()
 BACKEND_API_KEY = os.getenv("NATURALCAD_API_KEY", os.getenv("NL_CAD_API_KEY", ""))
 BACKEND_TIMEOUT_SECONDS = float(os.getenv("NATURALCAD_BACKEND_TIMEOUT", "60"))
+SHOW_GENERATED_CODE = os.getenv("NATURALCAD_SHOW_CODE", "false").strip().lower() in {"1", "true", "yes", "on"}
 ARTIFACTS_DIR = Path(__file__).parent.parent / "artifacts"
 RUNS_DIR = ARTIFACTS_DIR / "runs"
 LOGS_DIR = ARTIFACTS_DIR / "logs"
@@ -552,7 +553,10 @@ def generate_from_prompt(prompt: str, mode: str, output_type: str):
                         print(f"DEBUG: STEP download failed: {e}")
                         step_file = None
                 
-                combined_logs = f"Generated build123d code:\n\n{code}\n\n"
+                if SHOW_GENERATED_CODE:
+                    combined_logs = f"Generated build123d code:\n\n{code}\n\n"
+                else:
+                    combined_logs = "Generation complete. (Code hidden; set NATURALCAD_SHOW_CODE=true to display.)\n\n"
                 combined_logs += "Execution complete. Artifacts uploaded to Supabase."
                 if job_id:
                     combined_logs += f"\nJob ID: {job_id}"