feat(api): add client lookup by subscription ID (#6908)

Integrations could only find a client by subscription ID through a substring
search over the paged client list followed by a second lookup by email.
GET /panel/api/clients/get/subId/:subId now returns the full client records
(settings, attached inbounds, external links, traffic, tunnel addresses) for an
exact subId match, as a list because older rows may share an ID. It sits behind
the same admin login or admin-token check as the email lookup.

internal/web/controller/client.go

@@ -13,6 +13,7 @@ import (
 	"github.com/mhsanaei/3x-ui/v3/internal/web/websocket"
 
 	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
 )
 
 func notifyClientsChanged() {
@@ -53,6 +54,7 @@ func (a *ClientController) initRouter(g *gin.RouterGroup) {
 	g.GET("/list", a.list)
 	g.GET("/list/paged", a.listPaged)
 	g.GET("/get/:email", a.get)
+	g.GET("/get/subId/:subId", a.getBySubId)
 	g.GET("/get/tgId/:tgId", a.getByTgId)
 	g.GET("/traffic/:email", a.getTrafficByEmail)
 	g.GET("/subLinks/:subId", a.getSubLinks)
@@ -172,6 +174,27 @@ func (a *ClientController) get(c *gin.Context) {
 	jsonObj(c, payload, nil)
 }
 
+func (a *ClientController) getBySubId(c *gin.Context) {
+	records, err := a.clientService.GetRecordsBySubID(c.Param("subId"))
+	if err == nil && len(records) == 0 {
+		err = gorm.ErrRecordNotFound
+	}
+	if err != nil {
+		jsonMsg(c, I18nWeb(c, "pages.inbounds.toasts.obtain"), err)
+		return
+	}
+	results := make([]gin.H, 0, len(records))
+	for _, rec := range records {
+		payload, err := a.buildClientPayload(rec)
+		if err != nil {
+			jsonMsg(c, I18nWeb(c, "pages.inbounds.toasts.obtain"), err)
+			return
+		}
+		results = append(results, payload)
+	}
+	jsonObj(c, results, nil)
+}
+
 func (a *ClientController) getByTgId(c *gin.Context) {
 	tgIdStr := c.Param("tgId")
 	tgId, err := strconv.ParseInt(tgIdStr, 10, 64)