feat(xray): add the MASQUE protocol and transport

xray-core v26.10.10 serves MASQUE: CONNECT-IP over HTTP/3 or HTTP/2,
always behind TLS, as an inbound and an outbound protocol riding a
dedicated "masque" transport. The panel could not create either.

Inbound: MASQUE is a multi-user protocol whose users log in with their
email and password over Basic auth. The panel keeps the client's
"password" like trojan and GenXrayInboundConfig hands it to the core as
"pass", so the full-config path, the live AddInbound path and node
pushes all emit what the core reads; one user with an empty pass makes
the core refuse the whole inbound. Live user adds build a masque.Account
from either key, client-only changes diff per user so a new client does
not drop every connected tunnel, and client creation, copy, validation
and edits key on the password. The address pool and MTU get form
fields, TLS is mandatory, and the port check follows the core's
listener choice: HTTP/2 on TCP when the ALPN offers h2, HTTP/3 on UDP
when it offers h3 or not h2. Nodes may host MASQUE from v3.9.1, the
first panel release that knows to rename the password.

MASQUE has no share-link format, so links and Clash skip it; the JSON
subscription builds the client's masque outbound with its email and
password, and the subscription allowlist now lets a subId see MASQUE
inbounds at all. The IP-limit job, client pages and traffic tracking
list the protocol.

Outbound: the form edits the server, remote DNS, and the transport's
host, path, Basic credentials, headers and WARP block (enrolled key,
endpoint public key, tunnel addresses), which xray-core refuses next to
user/pass. The outbound test probes it through the core, since its
default HTTP/3 dial is UDP.

internal/database/model/model.go

@@ -34,6 +34,7 @@ const (
 	MTProto     Protocol = "mtproto"
 	AmneziaWG   Protocol = "amneziawg"
 	TUIC        Protocol = "tuic"
+	MASQUE      Protocol = "masque"
 )
 
 // User represents a user account in the 3x-ui panel.
@@ -371,6 +372,10 @@ func (i *Inbound) GenXrayInboundConfig() *xray.InboundConfig {
 		if healed, ok := HealHysteriaVersion(settings); ok {
 			settings = healed
 		}
+	case MASQUE:
+		if converted, ok := MasqueClientsToCore(settings); ok {
+			settings = converted
+		}
 	}
 	streamSettings := i.StreamSettings
 	if stripped, ok := StripInboundXhttpClientFields(streamSettings); ok {
@@ -426,6 +431,46 @@ func StripVmessClientSecurity(settings string) (string, bool) {
 	return string(out), true
 }
 
+// MasqueClientsToCore renames each client's panel "password" to the "pass" key the
+// MASQUE server reads; xray-core refuses the whole inbound when one user's pass is empty.
+func MasqueClientsToCore(settings string) (string, bool) {
+	if settings == "" {
+		return settings, false
+	}
+	var parsed map[string]any
+	if err := json.Unmarshal([]byte(settings), &parsed); err != nil {
+		return settings, false
+	}
+	clients, ok := parsed["clients"].([]any)
+	if !ok {
+		return settings, false
+	}
+	changed := false
+	for i := range clients {
+		cm, ok := clients[i].(map[string]any)
+		if !ok {
+			continue
+		}
+		password, has := cm["password"]
+		if !has {
+			continue
+		}
+		if _, set := cm["pass"]; !set {
+			cm["pass"] = password
+		}
+		delete(cm, "password")
+		changed = true
+	}
+	if !changed {
+		return settings, false
+	}
+	out, err := json.MarshalIndent(parsed, "", "  ")
+	if err != nil {
+		return settings, false
+	}
+	return string(out), true
+}
+
 // WireguardPeerFromClient builds the xray wireguard inbound peer object for one
 // WireGuard client. It is the single definition of the peer shape, shared by the
 // full-config path (XrayService.GetXrayConfig) and the live AddInbound path