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/QuoteCalculateRequest.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace App\Http\Requests\Quote;
+
+use App\Models\Quote\Quote;
+use Illuminate\Foundation\Http\FormRequest;
+
+class QuoteCalculateRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'product_category' => 'nullable|in:'.Quote::CATEGORY_SCREEN.','.Quote::CATEGORY_STEEL,
+
+            // 입력값 (직접 또는 inputs 객체로)
+            'inputs' => 'nullable|array',
+
+            // 공통 입력
+            'W0' => 'nullable|numeric|min:0',
+            'H0' => 'nullable|numeric|min:0',
+            'QTY' => 'nullable|integer|min:1',
+            'inputs.W0' => 'nullable|numeric|min:0',
+            'inputs.H0' => 'nullable|numeric|min:0',
+            'inputs.QTY' => 'nullable|integer|min:1',
+
+            // 스크린 제품 입력
+            'INSTALL_TYPE' => 'nullable|in:wall,ceiling,floor',
+            'MOTOR_TYPE' => 'nullable|in:standard,heavy',
+            'CONTROL_TYPE' => 'nullable|in:switch,remote,smart',
+            'CHAIN_SIDE' => 'nullable|in:left,right',
+            'inputs.INSTALL_TYPE' => 'nullable|in:wall,ceiling,floor',
+            'inputs.MOTOR_TYPE' => 'nullable|in:standard,heavy',
+            'inputs.CONTROL_TYPE' => 'nullable|in:switch,remote,smart',
+            'inputs.CHAIN_SIDE' => 'nullable|in:left,right',
+
+            // 철재 제품 입력
+            'MATERIAL' => 'nullable|in:ss304,ss316,galvanized',
+            'THICKNESS' => 'nullable|numeric|min:0.1|max:50',
+            'FINISH' => 'nullable|in:hairline,mirror,matte',
+            'WELDING' => 'nullable|in:tig,mig,spot',
+            'inputs.MATERIAL' => 'nullable|in:ss304,ss316,galvanized',
+            'inputs.THICKNESS' => 'nullable|numeric|min:0.1|max:50',
+            'inputs.FINISH' => 'nullable|in:hairline,mirror,matte',
+            'inputs.WELDING' => 'nullable|in:tig,mig,spot',
+        ];
+    }
+}