Add piece_weight calibration: enter Stück + Gramm per delivery, average auto-calculated

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

app/Models/SpiceSupplier.php

@@ -15,6 +15,7 @@ class SpiceSupplier extends Model
         'spice_id',
         'supplier_id',
         'amount',
+        'weight_g',
         'supplied_at',
     ];
 
@@ -39,6 +40,9 @@ class SpiceSupplier extends Model
                 'description' => 'Lieferung' . ($ss->supplier ? ' von ' . $ss->supplier->name : ''),
             ]);
             $ss->spice->recalculateQuantity();
+            if ($ss->weight_g && $ss->amount) {
+                $ss->spice->recalculatePieceWeight();
+            }
         });
 
         static::deleted(function (SpiceSupplier $ss) {
@@ -46,6 +50,9 @@ class SpiceSupplier extends Model
                 ->where('source_id', $ss->id)
                 ->delete();
             $ss->spice->recalculateQuantity();
+            if ($ss->weight_g) {
+                $ss->spice->recalculatePieceWeight();
+            }
         });
     }
 }