Refactor video handling and integrate new services

- Removed legacy video handling code and models to streamline the codebase.
- Updated main.go to include new services for removing watermarks and smoke logging.
- Enhanced route registration to accommodate new handlers for watermark removal and smoke logging.
- Improved database migration to include new models for watermark processing.

internal/middleware/current_user.go

@@ -0,0 +1,18 @@
+package middleware
+
+import (
+	"github.com/gin-gonic/gin"
+
+	"wx_service/internal/model"
+)
+
+// CurrentUser 从 gin.Context 中取出鉴权中间件写入的当前用户。
+// 返回值 ok=false 表示：未经过鉴权中间件，或 token 无效导致未设置用户。
+func CurrentUser(c *gin.Context) (*model.User, bool) {
+	userVal, exists := c.Get(ContextCurrentUserKey)
+	if !exists {
+		return nil, false
+	}
+	user, ok := userVal.(*model.User)
+	return user, ok
+}