fix : avg runtime in roi graph

app.py

@@ -1130,19 +1130,19 @@ def create_combined_roi_time_series_graph(df):
         )
         return fig
     
-    # Define fixed start date (May 15, 2025)
-    fixed_start_date = datetime(2025, 5, 15)
-    logger.info(f"Using fixed start date for ROI runtime calculation: {fixed_start_date}")
+    # Calculate runtime for each agent from their actual first data point
+    logger.info(f"Calculating runtime for each agent from their actual start date")
     
-    # Calculate runtime for each agent from fixed start date
     agent_runtimes = {}
     for agent_id in df['agent_id'].unique():
         agent_data = df[df['agent_id'] == agent_id]
         agent_name = agent_data['agent_name'].iloc[0]
-        last_report = agent_data['timestamp'].max()
-        runtime_days = (last_report - fixed_start_date).total_seconds() / (24 * 3600)  # Convert to days
+        first_report = agent_data['timestamp'].min()  # Agent's actual start date
+        last_report = agent_data['timestamp'].max()   # Agent's last report
+        runtime_days = (last_report - first_report).total_seconds() / (24 * 3600)  # Convert to days
         agent_runtimes[agent_id] = {
             'agent_name': agent_name,
+            'first_report': first_report,
             'last_report': last_report,
             'runtime_days': runtime_days
         }