feat(inbound): excludeFromSub hides links without disabling (#6463)

* feat(inbound): excludeFromSub hides links without disabling

Add a per-inbound flag that omits subscription output while keeping the
inbound enabled for Xray, auth, and traffic accounting. Fixes #6435.

* fix(inbound): excludeFromSub review follow-ups

gofumpt model.go, sync docs OpenAPI, keep excludeFromSub master-authored
on node mirror, and exercise the legacy add-column migration path in tests.

* fix(sub): keep excluded inbounds' clients in the usage header

The excludeFromSub filter sat in getInboundsBySubId's SQL, so an excluded
inbound's clients never reached seenEmails in the raw, Clash or JSON
renderer. A client that lives only on a hidden inbound (one client per
inbound sharing a subId) dropped out of the Subscription-Userinfo usage,
quota and expiry and out of the info-node state, while the inbound kept
serving it and counting its traffic.

The query returns every enabled inbound again; each renderer skips an
excluded inbound's links but still counts its clients, the same rule the
Clash renderer already applies to external links it cannot express.

---------

Co-authored-by: mrchatam <mrchatam@users.noreply.github.com>
Co-authored-by: MHSanaei <ho3ein.sanaei@gmail.com>

internal/sub/json_service.go

@@ -141,6 +141,12 @@ func (s *SubJsonService) GetJson(subId string, host string, alwaysReturnArray bo
 		if len(clients) == 0 {
 			continue
 		}
+		if inbound.ExcludeFromSub {
+			if countHiddenClients(clients, seenEmails) {
+				hasEnabledClient = true
+			}
+			continue
+		}
 		subReq.projectThroughFallbackMaster(inbound)
 		if hostEps := subReq.hostEndpoints(inbound, "json"); len(hostEps) > 0 {
 			injectExternalProxy(inbound, hostEps)