feat: 트리거 감사로그 operation_id 컬럼 추가 및 요청별 UUID 설정

- trigger_audit_logs 테이블에 operation_id(VARCHAR 36) 컬럼 추가
- ix_trig_operation 인덱스 생성 (일괄 롤백 조회용)
- SetAuditSessionVariables 미들웨어에서 요청마다 @sam_operation_id UUID 설정

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

database/migrations/2026_02_13_100000_add_operation_id_to_trigger_audit_logs.php

@@ -0,0 +1,28 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\DB;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        // 파티셔닝된 테이블에 컬럼 추가
+        DB::statement("
+            ALTER TABLE trigger_audit_logs
+            ADD COLUMN operation_id VARCHAR(36) DEFAULT NULL COMMENT '작업 단위 ID (요청별 UUID)' AFTER session_info
+        ");
+
+        // operation_id 인덱스 (일괄 롤백 조회용)
+        DB::statement("
+            CREATE INDEX ix_trig_operation
+                ON trigger_audit_logs (operation_id, created_at)
+        ");
+    }
+
+    public function down(): void
+    {
+        DB::statement('DROP INDEX ix_trig_operation ON trigger_audit_logs');
+        DB::statement('ALTER TABLE trigger_audit_logs DROP COLUMN operation_id');
+    }
+};