优化: 前后端字段对齐、AI分析JSON解析修复、AutoMigrate

- 修复登录参数 username→account
- 修复前后端字段名不匹配 (ticketno/contactname/createtime等)
- 修复AI分析GLM返回markdown包裹和priority类型问题
- 添加AutoMigrate自动建表
- 统一API路由为 /api/auth/ 前缀
- 添加config.example.yaml，.gitignore排除config.yaml

backend/internal/service/ticket_service.go

@@ -14,20 +14,20 @@ type TicketListResult struct {
 	Rows  []model.TicketInfo `json:"rows"`
 }
 
-func ListTickets(db *gorm.DB, status int16, category string, priority int16, keyword string, page, pageSize int) (*TicketListResult, error) {
+func ListTickets(db *gorm.DB, status *int16, category string, priority *int16, keyword string, page, pageSize int) (*TicketListResult, error) {
 	var total int64
 	var tickets []model.TicketInfo
 
 	query := db.Model(&model.TicketInfo{})
 
-	if status >= 0 {
-		query = query.Where("status = ?", status)
+	if status != nil {
+		query = query.Where("status = ?", *status)
 	}
 	if category != "" {
 		query = query.Where("category = ?", category)
 	}
-	if priority >= 0 {
-		query = query.Where("priority = ?", priority)
+	if priority != nil {
+		query = query.Where("priority = ?", *priority)
 	}
 	if keyword != "" {
 		query = query.Where("title LIKE ? OR content LIKE ?", "%"+keyword+"%", "%"+keyword+"%")