General issue Go. Why isn't the following code recognized as a source in a global data stream?

Why isn't the following code recognized as a source in a global data stream? If I want to identify this source in the global data stream, how should I write my QL?

Here's the code context：

```
//router.go
func RegisterServers(group *gin.RouterGroup) {
group.POST("/abc/test", val.Validate[*param.TestParam], controller.TestReadFile)
}
```

```
//controller.go
func TestReadFile(c *gin.Context) {
req := val.Get[*param.TestParam](c)
cleanPath := req.Path
file, err := os.Open(cleanPath)
if err != nil {
if os.IsNotExist(err) {
c.JSON(http.StatusNotFound, gin.H{"error": "file not found"})
} else {
c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to open file"})
}
return
}
......
}
```

```
//validator.go
package val
func Validate[T any](ctx *gin.Context) {
var req T
if err := ctx.ShouldBindJSON(&req); err != nil {
ctx.JSON(http.StatusBadRequest, gin.H{"code": constant.UnknownErrorCode, "msg": util.GetErrorText(constant.UnknownErrorCode)})
ctx.Abort()
return
}
ctx.Set("params", req)
ctx.Next()
}

func Get[T any](ctx *gin.Context) T {
return ctx.MustGet("params").(T)
}
```

```
//param.go
package param

type TestParam struct {
Path string `json:"filepath"`
}
```

I found that the default "ActiveThreatModelSource" in the official rule "TainterPath.ql" is not recognizable as a source by the above code.
Here's the code I wrote to try to add a new class about this kind of source, and I use "req" from "req.Path" as the source, although the result can be recognized when "Quick Evaluation" is used, but when it is run in the whole "TaintTracking::Global", it cannot be recognized that there is a problem with this "controller.go".
```
class GinContextGetSource extends DataFlow::Node {
GinContextGetSource() {
exists(Function asmGet, CallExpr call |
asmGet.hasQualifiedName("project/router/val", "Get")
and call.getTarget() = asmGet
and call.getEnclosingFunction() = this.asExpr().getEnclosingFunction()
and this.asExpr().toString() = "req"
and this.asExpr().getEnclosingFunction().getAParameter().toString() = "c"
)
}
}
```

I need to address this issue urgently. Because the routing and controller parts of the entire Gin project that I am currently responsible for are developed in this form, the global data flow in each of my official rules cannot be identified in any of the sources
Thank you so much!