Add finalMask field for WireGuard

https://github.com/2dust/v2rayNG/issues/5891

V2rayNG/app/src/main/java/com/v2ray/ang/core/CoreOutboundBuilder.kt

@@ -264,6 +264,13 @@ object CoreOutboundBuilder {
             wireguard.reserved = profileItem.reserved?.takeIf { it.isNotBlank() }?.split(",")?.filter { it.isNotBlank() }?.map { it.trim().toInt() }
         }
 
+        if (!profileItem.finalMask.isNullOrBlank()) {
+            outboundBean?.streamSettings = OutboundBean.StreamSettingsBean()
+            outboundBean?.streamSettings?.let {
+                updateOutboundFinalMask(it, profileItem)
+                it.network = null
+            }
+        }
         return outboundBean
     }
 
@@ -670,4 +677,16 @@ object CoreOutboundBuilder {
         }
         return resolvedIps.first()
     }
+
+    fun updateOutboundFinalMask(streamSettings: OutboundBean.StreamSettingsBean, profileItem: ProfileItem) {
+        val finalMask = profileItem.finalMask
+        finalMask?.let {
+            val parsedFinalMask = JsonUtil.parseString(profileItem.finalMask)
+            if (parsedFinalMask != null) {
+                streamSettings.finalmask = parsedFinalMask
+            } else {
+                LogUtil.w("V2rayConfigManager", "Invalid finalMask JSON, keeping previously generated finalmask")
+            }
+        }
+    }
 }

V2rayNG/app/src/main/java/com/v2ray/ang/dto/V2rayConfig.kt

@@ -108,7 +108,7 @@ data class V2rayConfig(
         }
 
         data class StreamSettingsBean(
-            var network: String = AppConfig.DEFAULT_NETWORK,
+            var network: String? = AppConfig.DEFAULT_NETWORK,
             var security: String? = null,
             var tcpSettings: TcpSettingsBean? = null,
             var kcpSettings: KcpSettingsBean? = null,

V2rayNG/app/src/main/java/com/v2ray/ang/ui/server/ServerWireguardActivity.kt

@@ -69,6 +69,12 @@ class ServerWireguardActivity : BaseServerActivity() {
             { state.mtu = it },
             keyboardType = KeyboardType.Number
         )
+
+        FormTextField(
+            stringResource(R.string.server_lab_final_mask),
+            state.finalMask,
+            { state.finalMask = it }
+        )
     }
 }