fixed asc_file.stem issue

app.py

@@ -257,7 +257,7 @@ def process_trial_choice(trial_id, algo_choice):
     if "dffix" in trial:
         dffix = trial["dffix"]
     else:
-        asc_file = st.session_state["asc_file"]
+        asc_file = pl.Path(st.session_state["asc_file"].name)
         trial["plot_file"] = str(PLOTS_FOLDER.joinpath(f"{asc_file.stem}_{trial_id}_2ndInput_chars_channel_sep.png"))
         trial["fname"] = str(asc_file.name).split(".")[0]
         df, dffix, trial = ut.trial_to_dfs(trial, st.session_state["lines"], use_synctime=True)