Warenwirtschaft: AP-27 Wareneingang gleiche Charge zusammenführen

- Chargen-Existenz-Check beim Buchen (JSON-Endpoint batch-check): Hinweis
  „Charge bereits im Haus" + Vorbelegung MHD/Qualität aus dem letzten Eingang
- Rohstoffbestand-Detail: Chargen je batch_number summiert
  (InventoryService::chargeGroupsForIngredient), Einkäufe als Unterzeilen
- Produktion: Charge-Dropdown je Charge mit Summen-Rest (batches im
  Recipe-Payload), Verbrauch wird per expandBatchLines FEFO auf die
  Einzel-Einkäufe der Charge verteilt; Service-API bleibt je stock_entry
- Jeder Einkauf bleibt eigener stock_entry (Preis/Datum/Audit)
- Hinweise-Doku + Plan V6.0 §6 fortgeschrieben

Tests: StockEntryChargeMergeTest (7 neu); Suite 193 grün, 698 Assertions

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

app/Http/Controllers/Admin/Inventory/ProductionController.php

@@ -53,6 +53,12 @@ class ProductionController extends Controller
         $payload = $request->validatedPayload();
 
         try {
+            // AP-27: Chargen-Zeilen (batch_key) FEFO auf die Einzel-Wareneingänge der Charge auflösen.
+            $ingredientLines = $this->productionService->expandBatchLines(
+                $payload['ingredient_lines'],
+                $payload['location_id']
+            );
+
             $production = $this->productionService->store(
                 [
                     'product_id' => $payload['product_id'],
@@ -61,7 +67,7 @@ class ProductionController extends Controller
                     'quantity' => $payload['quantity'],
                     'notes' => $payload['notes'],
                 ],
-                $payload['ingredient_lines'],
+                $ingredientLines,
                 (int) $request->user()->id
             );
         } catch (ValidationException $e) {
@@ -119,6 +125,13 @@ class ProductionController extends Controller
         $payload = $request->validatedPayload();
 
         try {
+            // AP-27: Beim Bearbeiten die eigene Produktion aus der Rest-Berechnung ausnehmen.
+            $ingredientLines = $this->productionService->expandBatchLines(
+                $payload['ingredient_lines'],
+                $payload['location_id'],
+                $production->id
+            );
+
             $production = $this->productionService->updateProduction(
                 $production,
                 [
@@ -128,7 +141,7 @@ class ProductionController extends Controller
                     'quantity' => $payload['quantity'],
                     'notes' => $payload['notes'],
                 ],
-                $payload['ingredient_lines'],
+                $ingredientLines,
                 (int) $request->user()->id
             );
         } catch (ValidationException $e) {

app/Http/Controllers/Admin/Inventory/RawMaterialStockController.php

@@ -5,7 +5,6 @@ namespace App\Http\Controllers\Admin\Inventory;
 use App\Http\Controllers\Controller;
 use App\Models\Ingredient;
 use App\Models\Location;
-use App\Models\StockEntry;
 use App\Models\TaxRate;
 use App\Repositories\StockEntryRepository;
 use App\Services\InventoryService;
@@ -76,8 +75,9 @@ class RawMaterialStockController extends Controller
             'products' => fn ($q) => $q->where('active', true),
         ]);
 
-        $charges = $this->inventoryService->chargesWithRemainingForIngredient($ingredient->id);
-        $remaining = round((float) $charges->sum(fn (StockEntry $entry) => (float) $entry->getAttribute('remaining_quantity')), 2);
+        // AP-27: Chargen je batch_number zusammengeführt (jeder Einkauf bleibt eigener stock_entry).
+        $chargeGroups = $this->inventoryService->chargeGroupsForIngredient($ingredient->id);
+        $remaining = round((float) $chargeGroups->sum('remaining'), 2);
 
         $remainingByLocation = $this->inventoryService->remainingByLocationForIngredient($ingredient->id);
 
@@ -95,7 +95,7 @@ class RawMaterialStockController extends Controller
         return view('admin.inventory.raw-material-stock.show', [
             'ingredient' => $ingredient,
             'productStock' => $productStock,
-            'charges' => $charges,
+            'chargeGroups' => $chargeGroups,
             'remaining' => round($remaining, 2),
             'remainingByLocation' => $remainingByLocation,
             'locations' => Location::query()->where('active', true)->orderBy('name')->get(),

app/Http/Controllers/Admin/Inventory/StockEntryController.php

@@ -14,6 +14,7 @@ use App\Models\StockEntry;
 use App\Models\Supplier;
 use App\Models\TaxRate;
 use App\Repositories\StockEntryRepository;
+use App\Services\InventoryService;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
@@ -201,6 +202,51 @@ class StockEntryController extends Controller
         return redirect()->route('admin.inventory.stock-entries.show', $stockEntry->fresh());
     }
 
+    /**
+     * AP-27: Existenz-Check beim Buchen des Wareneingangs — ist die Charge
+     * (batch_number + ingredient_id) schon im Haus? Liefert Hinweis-Daten
+     * und Vorbelegungswerte (MHD/Qualität) aus dem letzten Eingang der Charge.
+     */
+    public function batchCheck(Request $request, InventoryService $inventoryService): JsonResponse
+    {
+        $ingredientId = (int) $request->query('ingredient_id');
+        $batchNumber = trim((string) $request->query('batch_number', ''));
+        $excludeId = (int) $request->query('exclude', 0);
+
+        if ($ingredientId < 1 || $batchNumber === '') {
+            return response()->json(['exists' => false]);
+        }
+
+        $entries = StockEntry::query()
+            ->with('location')
+            ->where('entry_type', 'ingredient')
+            ->where('status', 'received')
+            ->where('ingredient_id', $ingredientId)
+            ->where('batch_number', $batchNumber)
+            ->when($excludeId > 0, fn ($q) => $q->where('id', '!=', $excludeId))
+            ->orderByDesc('received_at')
+            ->orderByDesc('id')
+            ->get();
+
+        if ($entries->isEmpty()) {
+            return response()->json(['exists' => false]);
+        }
+
+        $latest = $entries->first();
+        $remaining = $inventoryService->chargesWithRemainingForIngredient($ingredientId)
+            ->filter(fn (StockEntry $e) => trim((string) $e->batch_number) === $batchNumber && $e->id !== $excludeId)
+            ->sum(fn (StockEntry $e) => (float) $e->getAttribute('remaining_quantity'));
+
+        return response()->json([
+            'exists' => true,
+            'purchases' => $entries->count(),
+            'remaining' => round((float) $remaining, 2),
+            'best_before' => $latest->best_before?->format('d.m.Y'),
+            'location' => $latest->location?->name,
+            'quality_id' => $latest->quality_id,
+        ]);
+    }
+
     public function searchIngredients(Request $request): JsonResponse
     {
         $term = trim((string) $request->query('q', ''));