feat(clients): selective bulk attach + new bulk detach

Inbounds page:
- AttachClientsModal now shows a per-client selection table (email,
  comment, enabled tag) with search and a live "selected of total"
  counter; all clients are pre-selected so the old "attach all"
  workflow stays a single OK click.
- New DetachClientsModal on the inbound row menu lets you pick which
  clients to remove from that inbound (records are kept so they can be
  re-attached later; for full removal use Delete).

Clients page:
- New "Attach (N)" bulk-action button + BulkAttachInboundsModal that
  attaches selected clients to one or more multi-user inbounds.
- New "Detach (N)" bulk-action button + BulkDetachInboundsModal that
  removes selected clients from chosen inbounds; (email, inbound) pairs
  where the client isn't attached are silently skipped.

Backend adds POST /panel/api/clients/bulkDetach, wrapping the existing
Detach service for each email and reporting per-email
detached/skipped/errors. ClientRecord rows are kept on detach to match
the single-client endpoint; bulkDel remains the path for full removal.

web/controller/client.go

@@ -49,6 +49,7 @@ func (a *ClientController) initRouter(g *gin.RouterGroup) {
 	g.POST("/bulkCreate", a.bulkCreate)
 	g.POST("/bulkAssignGroup", a.bulkAssignGroup)
 	g.POST("/bulkAttach", a.bulkAttach)
+	g.POST("/bulkDetach", a.bulkDetach)
 	g.POST("/resetTraffic/:email", a.resetTrafficByEmail)
 	g.POST("/updateTraffic/:email", a.updateTrafficByEmail)
 	g.POST("/ips/:email", a.getIps)
@@ -263,6 +264,29 @@ func (a *ClientController) bulkAttach(c *gin.Context) {
 	notifyClientsChanged()
 }
 
+type bulkDetachRequest struct {
+	Emails     []string `json:"emails"`
+	InboundIds []int    `json:"inboundIds"`
+}
+
+func (a *ClientController) bulkDetach(c *gin.Context) {
+	var req bulkDetachRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		jsonMsg(c, I18nWeb(c, "somethingWentWrong"), err)
+		return
+	}
+	result, needRestart, err := a.clientService.BulkDetach(&a.inboundService, req.Emails, req.InboundIds)
+	if err != nil {
+		jsonMsg(c, I18nWeb(c, "somethingWentWrong"), err)
+		return
+	}
+	jsonObj(c, result, nil)
+	if needRestart {
+		a.xrayService.SetToNeedRestart()
+	}
+	notifyClientsChanged()
+}
+
 func (a *ClientController) bulkDelete(c *gin.Context) {
 	var req bulkDeleteRequest
 	if err := c.ShouldBindJSON(&req); err != nil {