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/main.go

@@ -8,6 +8,7 @@ import (
 	"github.com/casehub/ticket-workbench/internal/config"
 	"github.com/casehub/ticket-workbench/internal/handler"
 	"github.com/casehub/ticket-workbench/internal/middleware"
+	"github.com/casehub/ticket-workbench/internal/model"
 	"github.com/gin-gonic/gin"
 	"gorm.io/driver/mysql"
 	"gorm.io/gorm"
@@ -42,6 +43,16 @@ func main() {
 	sqlDB.SetMaxIdleConns(10)
 	sqlDB.SetMaxOpenConns(100)
 
+	if err := db.AutoMigrate(
+		&model.TicketUser{},
+		&model.TicketInfo{},
+		&model.TicketAiAnalysis{},
+		&model.TicketNote{},
+		&model.TicketOperationLog{},
+	); err != nil {
+		log.Fatalf("Failed to auto migrate: %v", err)
+	}
+
 	gin.SetMode(gin.ReleaseMode)
 	r := gin.Default()