debug: Add logging and warnings for Goal System issues

Based on test feedback - 3 issues addressed:

1. Primary Toggle (Frontend Debug):
   - Add console.log in handleSaveGoal
   - Shows what data is sent to backend
   - Helps debug if checkbox state is correct

2. Lean Mass Display (Backend Debug):
   - Add error handling in lean_mass calculation
   - Log why calculation fails (missing weight/bf data)
   - Try-catch for value conversion errors

3. BP/Strength/Flexibility Warning (UI):
   - Yellow warning box for incomplete goal types
   - BP: "benötigt 2 Werte (geplant für v2.0)"
   - Strength/Flexibility: "Keine Datenquelle"
   - Transparent about limitations

Next: User re-tests with debug output to identify root cause.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/routers/goals.py

@@ -444,10 +444,17 @@ def _get_current_value_for_goal_type(conn, profile_id: str, goal_type: str) -> O
         bf_row = cur.fetchone()
 
         if weight_row and bf_row:
+            try:
                 weight = float(weight_row['weight'])
                 bf_pct = float(bf_row['body_fat_pct'])
                 lean_mass = weight - (weight * bf_pct / 100.0)
                 return round(lean_mass, 2)
+            except (ValueError, TypeError) as e:
+                print(f"[DEBUG] lean_mass calculation error: {e}, weight={weight_row}, bf={bf_row}")
+                return None
+
+        # Debug: Log why calculation failed
+        print(f"[DEBUG] lean_mass calc failed - weight_row: {weight_row is not None}, bf_row: {bf_row is not None}")
         return None
 
     elif goal_type == 'vo2max':

frontend/src/pages/GoalsPage.jsx

@@ -167,6 +167,8 @@ export default function GoalsPage() {
         description: formData.description || null
       }
 
+      console.log('[DEBUG] Saving goal:', { editingGoal, data })
+
       if (editingGoal) {
         await api.updateGoal(editingGoal, data)
         showToast('✓ Ziel aktualisiert')
@@ -493,6 +495,24 @@ export default function GoalsPage() {
                   </option>
                 ))}
               </select>
+
+              {/* Warning for incomplete goal types */}
+              {['bp', 'strength', 'flexibility'].includes(formData.goal_type) && (
+                <div style={{
+                  marginTop: 8,
+                  padding: 8,
+                  background: '#FEF3C7',
+                  border: '1px solid #F59E0B',
+                  borderRadius: 6,
+                  fontSize: 12,
+                  color: '#92400E'
+                }}>
+                  ⚠️ Dieser Zieltyp ist aktuell eingeschränkt:
+                  {formData.goal_type === 'bp' && ' Blutdruck benötigt 2 Werte (geplant für v2.0)'}
+                  {formData.goal_type === 'strength' && ' Keine Datenquelle vorhanden (geplant für v2.0)'}
+                  {formData.goal_type === 'flexibility' && ' Keine Datenquelle vorhanden (geplant für v2.0)'}
+                </div>
+              )}
             </div>
 
             {/* Name */}