fitness profile fix

apps/mobile/src/app/(auth)/onboarding.tsx

@@ -96,9 +96,13 @@ export default function OnboardingScreen() {
 
       const fitnessData = {
         userId: user.id,
-        height: parseFloat(fitnessProfile.height),
-        weight: parseFloat(fitnessProfile.weight),
-        age: parseInt(fitnessProfile.age),
+        height: fitnessProfile.height
+          ? parseFloat(fitnessProfile.height)
+          : undefined,
+        weight: fitnessProfile.weight
+          ? parseFloat(fitnessProfile.weight)
+          : undefined,
+        age: fitnessProfile.age ? parseInt(fitnessProfile.age, 10) : undefined,
         fitnessGoals: fitnessProfile.goals ? [fitnessProfile.goals] : [],
         medicalConditions: fitnessProfile.medicalConditions || undefined,
         allergies: fitnessProfile.dietaryRestrictions || undefined,