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>

frontend/src/models/dbinbound.ts

@@ -44,6 +44,7 @@ export type DBInboundInit = Partial<{
   shareAddrStrategy: string;
   shareAddr: string;
   subSortIndex: number;
+  excludeFromSub: boolean;
   disableFlow: boolean;
   originNodeGuid: string;
   fallbackParent: FallbackParentRef | null;
@@ -93,6 +94,7 @@ export class DBInbound {
   shareAddrStrategy: string;
   shareAddr: string;
   subSortIndex: number;
+  excludeFromSub: boolean;
   disableFlow: boolean;
   originNodeGuid: string;
   fallbackParent: FallbackParentRef | null;
@@ -124,6 +126,7 @@ export class DBInbound {
     this.shareAddrStrategy = 'node';
     this.shareAddr = '';
     this.subSortIndex = 1;
+    this.excludeFromSub = false;
     this.disableFlow = false;
     this.originNodeGuid = '';
     this.fallbackParent = null;