feat: integrate cascade workflow

dea_api.py

@@ -15,6 +15,7 @@ from dea.csv_processing import (
     downsample_for_plot,
     filter_preview_response,
     filtered_csv_text,
+    preset_csv_metadata,
     save_csv_upload,
 )
 from dea.filter_design import design_response
@@ -97,6 +98,17 @@ def calculate_bode_compare_cascade(params: BodeCascadeParams):
         raise HTTPException(status_code=400, detail=str(e))
 
 
+@app.get("/api/csv/preset")
+def preset_csv():
+    try:
+        return preset_csv_metadata()
+    except HTTPException:
+        raise
+    except Exception as e:
+        traceback.print_exc()
+        raise HTTPException(status_code=400, detail=f"preset CSV 讀取失敗: {str(e)}")
+
+
 @app.post("/api/csv/upload")
 async def upload_csv(file: UploadFile = File(...)):
     try: