update timeline w multi

utils.py

@@ -513,8 +513,8 @@ def build_fig_treemap(df5, catTypeColors, speaker_color_map, get_display_name_fn
     return fig
 
 
-def build_fig_timeline(speakers_dataFrame, currTotalTime, speaker_color_map, get_display_name_fn, currFile):
-    """Gantt-style speaker timeline."""
+def build_fig_timeline(speakers_dataFrame, currTotalTime, speaker_color_map, get_display_name_fn, currFile, mv_intervals=None):
+    """Gantt-style speaker timeline with optional multi-voice vertical shading."""
     df = speakers_dataFrame.copy()
     df["Resource"] = df["Resource"].apply(lambda s: get_display_name_fn(s, currFile))
 
@@ -538,6 +538,18 @@ def build_fig_timeline(speakers_dataFrame, currTotalTime, speaker_color_map, get
     )
     fig.update_yaxes(autorange="reversed")
 
+    # Add vertical shading for multi-voice intervals
+    MV_COLOR = "#64A377"
+    for start_s, end_s in (mv_intervals or []):
+        fig.add_vrect(
+            x0=base + dt.timedelta(seconds=start_s),
+            x1=base + dt.timedelta(seconds=end_s),
+            fillcolor=MV_COLOR,
+            opacity=0.20,
+            layer="below",
+            line_width=0,
+        )
+
     h = int(currTotalTime // 3600)
     m = int(currTotalTime %  3600 // 60)
     s = int(currTotalTime %  60)