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>

docs/public/openapi.json

@@ -3054,6 +3054,11 @@
             "example": true,
             "type": "boolean"
           },
+          "excludeFromSub": {
+            "description": "Whether to omit this inbound from subscription output while keeping it operational",
+            "example": false,
+            "type": "boolean"
+          },
           "expiryTime": {
             "description": "Expiration timestamp",
             "format": "int64",
@@ -3177,6 +3182,7 @@
           "disableFlow",
           "down",
           "enable",
+          "excludeFromSub",
           "expiryTime",
           "id",
           "lastTrafficResetTime",
@@ -5162,6 +5168,7 @@
                       "disableFlow": false,
                       "down": 0,
                       "enable": true,
+                      "excludeFromSub": false,
                       "expiryTime": 0,
                       "fallbackParent": null,
                       "id": 1,
@@ -16250,6 +16257,7 @@
                   "disableFlow": false,
                   "down": 0,
                   "enable": true,
+                  "excludeFromSub": false,
                   "expiryTime": 0,
                   "fallbackParent": null,
                   "id": 1,