Enhance portfolio upload error handling and data integration in app.py

- Added error handling for portfolio file uploads to prevent crashes on invalid input.
- Integrated portfolio data with contest data for improved analysis and visibility.
- Adjusted logic to ensure the working dataframe is derived from the combined dataset when a portfolio is uploaded, enhancing user experience.

app.py

@@ -173,16 +173,20 @@ with tab1:
     with portfolio_upload:
         st.info("If you have a portfolio of lineups, you can upload them here to see how they would have performed against the field")
         st.session_state['portfolio_file'] = st.file_uploader("Upload Portfolio File (CSV or Excel)", type=['csv', 'xlsx', 'xls'])
-        st.session_state['portfolio_df'] = pd.read_csv(st.session_state['portfolio_file'])
-        original_columns = st.session_state['portfolio_df'].columns.tolist()
+        try:
+            st.session_state['portfolio_df'] = pd.read_csv(st.session_state['portfolio_file'])
         
-        for col in original_columns:
-            st.session_state['portfolio_df'][col] = st.session_state['portfolio_df'][col].astype(str).str.replace(r'\s*\([^)]*\)', '', regex=True).str.strip()
-        
-        st.session_state['portfolio_df']['BaseName'] = 'Backtesting_upload'
-        st.session_state['portfolio_df']['EntryCount'] = len(st.session_state['portfolio_df'])
-        
-        st.session_state['portfolio_df'] = st.session_state['portfolio_df'][['BaseName', 'EntryCount'] + original_columns]
+            original_columns = st.session_state['portfolio_df'].columns.tolist()
+            
+            for col in original_columns:
+                st.session_state['portfolio_df'][col] = st.session_state['portfolio_df'][col].astype(str).str.replace(r'\s*\([^)]*\)', '', regex=True).str.strip()
+            
+            st.session_state['portfolio_df']['BaseName'] = 'Backtesting_upload'
+            st.session_state['portfolio_df']['EntryCount'] = len(st.session_state['portfolio_df'])
+            
+            st.session_state['portfolio_df'] = st.session_state['portfolio_df'][['BaseName', 'EntryCount'] + original_columns]
+        except:
+            pass
             
 
     if 'Contest_file' in st.session_state:
@@ -208,6 +212,7 @@ with tab1:
             if 'portfolio_df' in st.session_state:
                 st.write('Portfolio data:')
                 st.dataframe(st.session_state['portfolio_df'].head(100))
+                st.session_state['combined_df'] = pd.concat([st.session_state['Contest'], st.session_state['portfolio_df']], ignore_index=True)
             else:
                 pass
         
@@ -240,7 +245,10 @@ with tab2:
         }
         
         # Create a copy of the dataframe for calculations
-        working_df = st.session_state['Contest'].copy()
+        if 'portfolio_df' in st.session_state:
+            working_df = st.session_state['combined_df'].copy()
+        else:
+            working_df = st.session_state['Contest'].copy()
         
         # Pre-compute lookup arrays for vectorized operations
         team_map = st.session_state['map_dict']['team_map']