adding cohort graph prototype

app.py

@@ -404,7 +404,6 @@ with demo:
             )
         with gr.TabItem("🪝 Retention metrics (WIP)"):
             with gr.Row():
-                # wow retention
                 gr.Markdown("# Wow retention by trader type")
             with gr.Row():
                 wow_retention = calculate_wow_retention_by_type(retention_df)
@@ -412,8 +411,12 @@ with demo:
                     wow_retention=wow_retention
                 )
             with gr.Row():
-                # cohort retention
                 gr.Markdown("# Cohort retention")
+            with gr.Row():
+                cohort_retention = calculate_cohort_retention(df=retention_df)
+                cohort_retention_plot = plot_cohort_retention_heatmap(
+                    retention_matrix=cohort_retention
+                )
 
         with gr.TabItem("⚙️ Active traders"):
             with gr.Row():