modify sheel name prefix: useu T3_ instead

app.py

@@ -62,7 +62,7 @@ def load_and_preview(file, n):
                         "power_dec","er_dec","power_meas","er_meas"
                     ]])
             if not rows:
-                raise ValueError("No valid sheets (prefix 'Tx 自動測試_') found in Excel file.")
+                raise ValueError("No valid sheets (prefix 'T3_') found in Excel file.")
             data_df = pd.concat(rows, ignore_index=True)
         elif ext == '.csv':
             # CSV format (exported)