fix(clients): stop a stale IP row from blocking a client edit

Saving a client walks every inbound it is attached to and calls
UpdateInboundClient, which re-keys the client's email in inbound_client_ips
to the spelling in the edited settings. The email match is EqualFold, so when
an inbound's settings JSON drifted in case from the client record the panel
issues a case-only rename of the tracking row.

inbound_client_ips.client_email is unique and case-sensitive, and the
IP-limit job keys its rows on whatever casing Xray reports, so both spellings
can already be present. The rename then aborts the whole edit with
"duplicate key value violates unique constraint
uni_inbound_client_ips_client_email" — the client could not be saved at all,
including when only adding an inbound to it.

The caller only renames onto an identity no live client holds, so a row on
the target email is stale IP tracking: delete it before renaming. The blob is
rebuilt by the next scan anyway.

internal/web/service/inbound_client_ips.go

@@ -152,6 +152,13 @@ func (s *InboundService) MergeInboundClientIps(incomingIps []model.InboundClient
 }
 
 func (s *InboundService) UpdateClientIPs(tx *gorm.DB, oldEmail string, newEmail string) error {
+	// The caller only renames onto a free identity, so a row already sitting on
+	// newEmail is stale tracking data — drop it instead of failing the edit.
+	if oldEmail != newEmail {
+		if err := tx.Where("client_email = ?", newEmail).Delete(model.InboundClientIps{}).Error; err != nil {
+			return err
+		}
+	}
 	return tx.Model(model.InboundClientIps{}).Where("client_email = ?", oldEmail).Update("client_email", newEmail).Error
 }