Add food item management and improve barcode workflow

Implemented routes and forms for adding and viewing food items by barcode, including templates for displaying and entering nutritional information. Enhanced the scan workflow to redirect to food item details or entry form. Added admin ability to delete food items. Improved UI for login and scan pages. Updated FoodItem model and form fields for consistency and accuracy.

forms.py

@@ -1,9 +1,27 @@
 from flask_wtf import FlaskForm
-from wtforms import StringField, PasswordField, SubmitField
-from wtforms.validators import DataRequired
+from wtforms import (
+    StringField,
+    PasswordField,
+    SubmitField,
+    IntegerField,
+    FloatField,
+)
+from wtforms.validators import DataRequired, InputRequired
 
 
 class LoginForm(FlaskForm):
     username = StringField("Username", validators=[DataRequired()])
     password = PasswordField("Password", validators=[DataRequired()])
     submit = SubmitField("Login")
+
+
+class FoodItemForm(FlaskForm):
+    barcode = IntegerField("Barcode", validators=[InputRequired()])
+    name = StringField("Product Name", validators=[DataRequired()])
+    energy = IntegerField("Energy per 100g", validators=[InputRequired()])
+    protein = FloatField("protein per 100g", validators=[InputRequired()])
+    carbs = FloatField("carbs per 100g", validators=[InputRequired()])
+    sugar = FloatField("sugar per 100g")
+    fat = FloatField("fat per 100g", validators=[InputRequired()])
+    saturated_fat = FloatField("saturated_fat per 100g")
+    submit = SubmitField("Add Item")