🐛 修复截图并发数初始化遗漏字段

- 初始化system_config时添加max_screenshot_concurrent字段

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

database.py

@@ -234,9 +234,9 @@ def init_database():
         try:
             cursor.execute('''
                 INSERT INTO system_config (
-                    id, max_concurrent_global, schedule_enabled,
+                    id, max_concurrent_global, max_concurrent_per_account, max_screenshot_concurrent,
-                    schedule_time, schedule_browse_type, schedule_weekdays
+                    schedule_enabled, schedule_time, schedule_browse_type, schedule_weekdays
-                ) VALUES (1, 2, 0, '02:00', '应读', '1,2,3,4,5,6,7')
+                ) VALUES (1, 2, 1, 3, 0, '02:00', '应读', '1,2,3,4,5,6,7')
             ''')
             conn.commit()
             print("✓ 已创建系统配置(默认并发2,定时任务关闭)")