refactor(app): address code review for #72

- 回环候选清单上收到 ListenerMode.compatibleLoopbackAddresses（Domain
  单点），proxyLoopbackAddress 派生为首项；策略不再复刻 mode→回环映射
- refreshCommandAddresses 更名 refreshTerminalCommands（返回命令的语义）
- 监视创建失败注明为尽力而为增强（进入首页/复制前刷新兜底）
- HTTPExportCapability 注释与首页完整命令的地址选择划清边界

ShadowsocksX-NG2/App/HomeView+Cards.swift

@@ -217,7 +217,7 @@ struct TerminalProxyEnvironmentCard: View {
       }
     )
     .onAppear {
-      control.refreshCommandAddresses()
+      control.refreshTerminalCommands()
     }
     .onDisappear {
       feedbackTask?.cancel()
@@ -261,7 +261,7 @@ struct TerminalProxyEnvironmentCard: View {
   private func copy(_ shell: TerminalCommandShell) {
     // 复制前刷新（issue #72）：失效选择回退后的命令即剪贴板内容，与按钮
     // 提示保持同一选择。
-    let commands = control.refreshCommandAddresses()
+    let commands = control.refreshTerminalCommands()
     do {
       try clipboard.write(shell.command(from: commands))
       feedbackTask?.cancel()

ShadowsocksX-NG2/App/ProxyControlWorkflow/ProxyControlAdapters.swift

@@ -81,8 +81,8 @@ final class ControllerProxyRuntimeAdapter: ProxyRuntimeAdapting {
   }
 }
 
-/// HTTP 导出能力的唯一派生点：监听设置 → 本机终端使用的可复制导出行。
-/// 环境变量始终指向回环地址，避免将命令误用于其他设备。
+/// HTTP 导出能力的唯一派生点：监听设置 → 可复制的 http/https 双导出行。
+/// 此导出行始终指向回环地址（与首页完整命令的命令地址选择无关，issue #72）。
 extension HTTPExportCapability {
   init(listen: SslocalListenSettings) {
     let urlHost = listen.proxyLoopbackURLHost

ShadowsocksX-NG2/App/ProxyControlWorkflow/ProxyControlWorkflow.swift

@@ -226,7 +226,7 @@ final class ProxyControlWorkflow: ObservableObject {
   /// 事实变化通知自动刷新）。返回刷新后的两种 shell 命令供剪贴板副作用
   /// 使用——失效选择已在本次观察中回退，提示投影与返回值一致。
   @discardableResult
-  func refreshCommandAddresses() -> TerminalProxyEnvironmentCommands {
+  func refreshTerminalCommands() -> TerminalProxyEnvironmentCommands {
     republish().terminalProxyEnvironmentCommands
   }
 

ShadowsocksX-NG2/App/ProxyControlWorkflow/SystemInterfaceFactsProvider.swift

@@ -28,6 +28,8 @@ final class SystemInterfaceFactsProvider: LocalInterfaceFactsReading {
   }
 
   private func startObserving() {
+    // 变化通知是尽力而为的增强：监视创建失败（罕见）只失去推送刷新，
+    // 进入首页与复制前刷新仍保证候选新鲜。
     var context = SCDynamicStoreContext(
       version: 0,
       info: Unmanaged.passUnretained(observation).toOpaque(),

ShadowsocksX-NG2/App/ProxyControlWorkflow/TerminalCommandAddress.swift

@@ -85,24 +85,19 @@ enum TerminalCommandAddressPolicy {
     return loopbacks + interfaceCandidates(mode: mode, interfaces: interfaces)
   }
 
-  /// 当前监听方式的默认回环地址（与 ListenerMode.proxyLoopbackAddress 一致）。
+  /// 当前监听方式的默认回环地址（Domain 回环清单首项）。
   static func defaultLoopback(for mode: ListenerMode) -> TerminalCommandAddress {
-    TerminalCommandAddress(bsdName: "lo0", address: mode.proxyLoopbackAddress, displayName: "lo0")
+    TerminalCommandAddress(
+      bsdName: "lo0", address: mode.proxyLoopbackAddress, displayName: "lo0")
   }
 
   // MARK: - 派生细节
 
+  /// 回环候选（置顶）直接来自 Domain 的监听方式回环清单，展示名固定 lo0。
   private static func loopbackCandidates(for mode: ListenerMode) -> [TerminalCommandAddress] {
-    let addresses: [String]
-    switch mode {
-    case .localhost, .allIPv4Interfaces:
-      addresses = ["127.0.0.1"]
-    case .allIPv4AndIPv6Interfaces:
-      addresses = ["127.0.0.1", "::1"]
-    case .allIPv6Interfaces:
-      addresses = ["::1"]
+    mode.compatibleLoopbackAddresses.map {
+      TerminalCommandAddress(bsdName: "lo0", address: $0, displayName: "lo0")
     }
-    return addresses.map { TerminalCommandAddress(bsdName: "lo0", address: $0, displayName: "lo0") }
   }
 
   /// 待排序的接口分组：显示名 + BSD 名 + 该接口的地址候选。

ShadowsocksX-NG2/Domain/SslocalRuntimeDocument.swift

@@ -25,8 +25,19 @@ enum ListenerMode: String, Codable, CaseIterable, Equatable, Sendable {
     }
   }
 
+  /// 此监听方式可接受的回环地址（默认地址在前）：IPv4/仅本机只接受
+  /// 127.0.0.1，双栈通配绑定同时接受两个回环族，仅 IPv6 只接受 ::1。
+  var compatibleLoopbackAddresses: [String] {
+    switch self {
+    case .localhost, .allIPv4Interfaces: ["127.0.0.1"]
+    case .allIPv4AndIPv6Interfaces: ["127.0.0.1", "::1"]
+    case .allIPv6Interfaces: ["::1"]
+    }
+  }
+
+  /// 健康探测、系统代理与 HTTP 导出行使用的默认兼容回环地址。
   var proxyLoopbackAddress: String {
-    self == .allIPv6Interfaces ? "::1" : "127.0.0.1"
+    compatibleLoopbackAddresses[0]
   }
 
   var bindingHint: String {

ShadowsocksX-NG2/Tests/ProxyCommandAddressWorkflowTests.swift

@@ -233,7 +233,7 @@ final class ProxyCommandAddressLifecycleTests: XCTestCase {
     let wifi = workflow.snapshot.commandAddressPicker.candidates[1]
     _ = workflow.selectCommandAddress(wifi)
 
-    _ = workflow.refreshCommandAddresses()  // 离开再进入首页
+    _ = workflow.refreshTerminalCommands()  // 离开再进入首页
 
     XCTAssertEqual(
       workflow.snapshot.commandAddressPicker.selected.identity, wifi.identity,
@@ -330,7 +330,7 @@ final class ProxyCommandAddressLifecycleTests: XCTestCase {
 
     // 复制前地址消失且变化通知丢失：复制前刷新发现失效。
     interfaceFacts.interfaces = []
-    let prepared = workflow.refreshCommandAddresses()
+    let prepared = workflow.refreshTerminalCommands()
 
     XCTAssertFalse(
       prepared.zshBash.contains("192.168.1.10"), "复制内容不包含已消失的地址")
@@ -348,7 +348,7 @@ final class ProxyCommandAddressLifecycleTests: XCTestCase {
     runtime.runtimeFacts = ProxyRuntimeFacts(status: .off, isOn: false)
     runtime.emitChange()
 
-    let prepared = workflow.refreshCommandAddresses()
+    let prepared = workflow.refreshTerminalCommands()
 
     XCTAssertTrue(prepared.zshBash.contains("127.0.0.1"), "代理未运行时命令仍可准备")
     XCTAssertEqual(runtime.resyncCount, 0, "刷新不触碰运行时生命周期")