feat(quote): quote_type 컬럼 추가 및 건설 견적 필터링 구현

- quotes 테이블에 quote_type 컬럼 추가 (manufacturing/construction)
- Quote 모델에 TYPE 상수 및 스코프 메서드 추가
- QuoteService.index()에 quote_type 필터 적용
- QuoteService.upsertFromSiteBriefing()에 construction 타입 설정
- QuoteIndexRequest에 quote_type 유효성 검증 추가
- 기존 site_briefing_id 있는 데이터는 construction으로 자동 업데이트

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

database/migrations/2026_01_12_210406_add_quote_type_to_quotes_table.php

@@ -0,0 +1,40 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::table('quotes', function (Blueprint $table) {
+            $table->string('quote_type', 20)
+                ->default('manufacturing')
+                ->after('tenant_id')
+                ->comment('견적 유형: manufacturing(제조), construction(시공)');
+
+            $table->index('quote_type', 'idx_quotes_quote_type');
+        });
+
+        // 기존 데이터: site_briefing_id가 있으면 construction으로 설정
+        DB::table('quotes')
+            ->whereNotNull('site_briefing_id')
+            ->update(['quote_type' => 'construction']);
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::table('quotes', function (Blueprint $table) {
+            $table->dropIndex('idx_quotes_quote_type');
+            $table->dropColumn('quote_type');
+        });
+    }
+};