Update app.py

app.py

@@ -720,7 +720,7 @@ NUTRIENT_CONTENT_IN_FERTILIZERS = {
 class NutrientCalculator:
     def __init__(self, volume_liters: float = 1.0):
         self.volume = volume_liters
-        self.results = {}
+        self.results: Dict[str, Dict[str, Any]] = {}
         self.target_profile = DEFAULT_VALUES['BASE_PROFILE'].copy()
         self.actual_profile = {k: 0.0 for k in DEFAULT_VALUES['BASE_PROFILE']}
         self.total_ec = 0.0
@@ -729,6 +729,7 @@ class NutrientCalculator:
             'CaNO3': 0.3,
             'K2SO4': 0.2
         }
+        self.fertilizers: Dict[str, Dict[str, float]] = {}
 
     def _label(self, element: str) -> str:
         labels = {