feat(API): Inspection API 구현

- InspectionController 생성 (CRUD + stats + complete)
- InspectionService 생성 (비즈니스 로직)
- FormRequest 생성 (Store/Update/Complete)
- 라우트 등록 (7개 엔드포인트)
- i18n 메시지 추가 (message.php, error.php)

기존 inspections 테이블 및 Inspection 모델 활용

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

app/Http/Requests/Inspection/InspectionStoreRequest.php

@@ -0,0 +1,47 @@
+<?php
+
+namespace App\Http\Requests\Inspection;
+
+use App\Models\Qualitys\Inspection;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class InspectionStoreRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'inspection_type' => ['required', Rule::in([
+                Inspection::TYPE_IQC,
+                Inspection::TYPE_PQC,
+                Inspection::TYPE_FQC,
+            ])],
+            'lot_no' => ['required', 'string', 'max:50'],
+            'item_name' => ['nullable', 'string', 'max:200'],
+            'process_name' => ['nullable', 'string', 'max:100'],
+            'quantity' => ['nullable', 'numeric', 'min:0'],
+            'unit' => ['nullable', 'string', 'max:20'],
+            'inspector_id' => ['nullable', 'integer', 'exists:users,id'],
+            'remarks' => ['nullable', 'string', 'max:1000'],
+            'items' => ['nullable', 'array'],
+            'items.*.name' => ['required_with:items', 'string', 'max:200'],
+            'items.*.type' => ['required_with:items', Rule::in(['quality', 'measurement'])],
+            'items.*.spec' => ['required_with:items', 'string', 'max:200'],
+            'items.*.unit' => ['nullable', 'string', 'max:20'],
+        ];
+    }
+
+    public function messages(): array
+    {
+        return [
+            'inspection_type.required' => __('validation.required', ['attribute' => '검사유형']),
+            'inspection_type.in' => __('validation.in', ['attribute' => '검사유형']),
+            'lot_no.required' => __('validation.required', ['attribute' => 'LOT번호']),
+        ];
+    }
+}