feat: [quote] 견적 API Phase 2-3 완료 (Service + Controller Layer)

Phase 2 - Service Layer:
- QuoteService: 견적 CRUD + 상태관리 (확정/전환)
- QuoteNumberService: 견적번호 채번 (KD-{PREFIX}-YYMMDD-SEQ)
- FormulaEvaluatorService: 수식 평가 엔진 (SUM, IF, ROUND 등)
- QuoteCalculationService: 자동산출 (스크린/철재 제품)
- QuoteDocumentService: PDF 생성 및 이메일/카카오 발송

Phase 3 - Controller Layer:
- QuoteController: 16개 엔드포인트
- FormRequest 7개: Index, Store, Update, BulkDelete, Calculate, SendEmail, SendKakao
- QuoteApi.php: Swagger 문서 (12개 스키마, 16개 엔드포인트)
- routes/api.php: 16개 라우트 등록

i18n 키 추가:
- error.php: quote_not_found, formula_* 등
- message.php: quote.* 성공 메시지

app/Http/Requests/Quote/QuoteStoreRequest.php

@@ -0,0 +1,86 @@
+<?php
+
+namespace App\Http\Requests\Quote;
+
+use App\Models\Quote\Quote;
+use Illuminate\Foundation\Http\FormRequest;
+
+class QuoteStoreRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            // 기본 정보
+            'quote_number' => 'nullable|string|max:50',
+            'registration_date' => 'nullable|date',
+            'receipt_date' => 'nullable|date',
+            'author' => 'nullable|string|max:50',
+
+            // 발주처 정보
+            'client_id' => 'nullable|integer',
+            'client_name' => 'nullable|string|max:100',
+            'manager' => 'nullable|string|max:50',
+            'contact' => 'nullable|string|max:50',
+
+            // 현장 정보
+            'site_id' => 'nullable|integer',
+            'site_name' => 'nullable|string|max:100',
+            'site_code' => 'nullable|string|max:50',
+
+            // 제품 정보
+            'product_category' => 'nullable|in:'.Quote::CATEGORY_SCREEN.','.Quote::CATEGORY_STEEL,
+            'product_id' => 'nullable|integer',
+            'product_code' => 'nullable|string|max:50',
+            'product_name' => 'nullable|string|max:100',
+
+            // 규격 정보
+            'open_size_width' => 'nullable|numeric|min:0',
+            'open_size_height' => 'nullable|numeric|min:0',
+            'quantity' => 'nullable|integer|min:1',
+            'unit_symbol' => 'nullable|string|max:10',
+            'floors' => 'nullable|string|max:50',
+
+            // 금액 정보
+            'material_cost' => 'nullable|numeric|min:0',
+            'labor_cost' => 'nullable|numeric|min:0',
+            'install_cost' => 'nullable|numeric|min:0',
+            'discount_rate' => 'nullable|numeric|min:0|max:100',
+            'total_amount' => 'nullable|numeric|min:0',
+
+            // 기타 정보
+            'completion_date' => 'nullable|date',
+            'remarks' => 'nullable|string|max:500',
+            'memo' => 'nullable|string',
+            'notes' => 'nullable|string',
+
+            // 자동산출 입력값
+            'calculation_inputs' => 'nullable|array',
+            'calculation_inputs.*' => 'nullable',
+
+            // 품목 배열
+            'items' => 'nullable|array',
+            'items.*.item_id' => 'nullable|integer',
+            'items.*.item_code' => 'nullable|string|max:50',
+            'items.*.item_name' => 'nullable|string|max:100',
+            'items.*.specification' => 'nullable|string|max:200',
+            'items.*.unit' => 'nullable|string|max:20',
+            'items.*.base_quantity' => 'nullable|numeric|min:0',
+            'items.*.calculated_quantity' => 'nullable|numeric|min:0',
+            'items.*.unit_price' => 'nullable|numeric|min:0',
+            'items.*.total_price' => 'nullable|numeric|min:0',
+            'items.*.formula' => 'nullable|string|max:500',
+            'items.*.formula_result' => 'nullable|string|max:200',
+            'items.*.formula_source' => 'nullable|string|max:100',
+            'items.*.formula_category' => 'nullable|string|max:50',
+            'items.*.data_source' => 'nullable|string|max:100',
+            'items.*.delivery_date' => 'nullable|date',
+            'items.*.note' => 'nullable|string|max:500',
+            'items.*.sort_order' => 'nullable|integer|min:0',
+        ];
+    }
+}