fix([2fd88f42]): handle malformed header in PLZ csv dataset

heatmap-tool/backend/main.py

@@ -26,13 +26,19 @@ def load_plz_data():
     global plz_geocoord_df
     try:
         print("--- Loading PLZ geocoordinates dataset... ---")
-        df = pd.read_csv("plz_geocoord.csv", dtype={'plz': str})
+        # The CSV has a malformed header. We read it and assign names manually.
+        df = pd.read_csv("plz_geocoord.csv", dtype=str)
+        # Rename the columns based on their expected order: PLZ, Latitude, Longitude
+        df.columns = ['plz', 'y', 'x']
+        
         df['plz'] = df['plz'].str.zfill(5)
         plz_geocoord_df = df.set_index('plz')
         print(f"--- Successfully loaded {len(plz_geocoord_df)} PLZ coordinates. ---")
     except FileNotFoundError:
         print("--- FATAL ERROR: plz_geocoord.csv not found. Geocoding will not work. ---")
-        # In a real app, you might want to exit or handle this more gracefully
+        plz_geocoord_df = pd.DataFrame()
+    except Exception as e:
+        print(f"--- FATAL ERROR loading plz_geocoord.csv: {e} ---")
         plz_geocoord_df = pd.DataFrame()
 
 # --- Pydantic Models ---