fix(purchase): purchase_requests 테이블 스키마 — item_id NULL + 직접입력/사진 컬럼

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

system1-factory/api/db/migrations/20260313100000_create_purchase_system.sql

@@ -33,10 +33,12 @@ CREATE TABLE IF NOT EXISTS consumable_items (
     UNIQUE KEY uq_name_maker (item_name, maker)
 );
 
--- 구매신청 (tkfb에서 CRUD)
+-- 구매신청 (tkfb에서 CRUD) — item_id NULL 허용 + 직접입력/사진 컬럼 추가
 CREATE TABLE IF NOT EXISTS purchase_requests (
     request_id INT AUTO_INCREMENT PRIMARY KEY,
-    item_id INT NOT NULL,
+    item_id INT NULL,
+    custom_item_name VARCHAR(100) NULL COMMENT '직접입력 품명',
+    custom_category ENUM('consumable','safety','repair','equipment') NULL COMMENT '직접입력 카테고리',
     quantity INT NOT NULL DEFAULT 1,
     requester_id INT NOT NULL COMMENT 'FK → sso_users.user_id',
     request_date DATE NOT NULL,
@@ -44,6 +46,7 @@ CREATE TABLE IF NOT EXISTS purchase_requests (
       COMMENT '대기, 구매완료, 보류',
     hold_reason TEXT,
     notes TEXT,
+    photo_path VARCHAR(255) NULL COMMENT '첨부 사진',
     created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
     updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     FOREIGN KEY (item_id) REFERENCES consumable_items(item_id),