Offer Tunnel as a network mode in Launchpad

Machine settings and New Machine list Tunnel next to NAT, Bridged and
None, with a line saying what it does. The inspector showed a tunnel
machine's network as None; it now says Tunnel.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

VPhoneLaunchpad/VPhoneLaunchpad/Localizable.xcstrings

@@ -1,6 +1,74 @@
 {
   "sourceLanguage" : "en",
   "strings" : {
+    "Tunnel" : {
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Tunnel"
+          }
+        },
+        "ja" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "トンネル"
+          }
+        },
+        "ko" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "터널"
+          }
+        },
+        "vi" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Đường hầm"
+          }
+        },
+        "zh-Hans" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "隧道"
+          }
+        }
+      }
+    },
+    "Traffic leaves through this Mac's own connections, so it follows the Mac's VPN." : {
+      "localizations" : {
+        "en" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Traffic leaves through this Mac's own connections, so it follows the Mac's VPN."
+          }
+        },
+        "ja" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "通信はこの Mac 自身の接続から送られるため、Mac の VPN を経由します。"
+          }
+        },
+        "ko" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "트래픽이 이 Mac의 자체 연결로 나가므로 Mac의 VPN을 따릅니다."
+          }
+        },
+        "vi" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "Lưu lượng đi qua các kết nối của chính máy Mac này, nên sẽ đi theo VPN của máy Mac."
+          }
+        },
+        "zh-Hans" : {
+          "stringUnit" : {
+            "state" : "translated",
+            "value" : "流量从这台 Mac 自己的连接发出，因此会经过 Mac 的 VPN。"
+          }
+        }
+      }
+    },
     "" : {
 
     },

VPhoneLaunchpad/VPhoneLaunchpad/Machines/VPhoneLaunchpadMachine.swift

@@ -107,6 +107,7 @@ nonisolated struct VPhoneLaunchpadMachine: Decodable, Hashable, Identifiable, Se
         switch network.mode {
         case "nat": String(localized: "NAT")
         case "bridged": network.bridgeInterface.map { String(localized: "Bridged to \($0)") } ?? String(localized: "Bridged")
+        case "tunnel": String(localized: "Tunnel")
         case "hostOnly": String(localized: "Host only")
         default: String(localized: "None")
         }

VPhoneLaunchpad/VPhoneLaunchpad/Machines/VPhoneLaunchpadMachineSheets.swift

@@ -46,11 +46,16 @@ struct VPhoneLaunchpadMachineSettingsView: View {
                     Picker("Mode", selection: $network) {
                         Text("NAT").tag("nat")
                         Text("Bridged").tag("bridged")
+                        Text("Tunnel").tag("tunnel")
                         Text("None").tag("none")
                     }
                     if network == "bridged" {
                         TextField("Interface", text: $bridgeInterface, prompt: Text("First available"))
                     }
+                    if network == "tunnel" {
+                        Text("Traffic leaves through this Mac's own connections, so it follows the Mac's VPN.")
+                            .foregroundStyle(.secondary)
+                    }
                 } header: {
                     Text("Network")
                 } footer: {

VPhoneLaunchpad/VPhoneLaunchpad/Machines/VPhoneLaunchpadNewMachineAdvancedView.swift

@@ -18,6 +18,7 @@ struct VPhoneLaunchpadNewMachineAdvancedView: View {
     static func networkTitle(_ mode: String) -> String {
         switch mode {
         case "bridged": String(localized: "Bridged")
+        case "tunnel": String(localized: "Tunnel")
         case "none": String(localized: "None")
         default: String(localized: "NAT")
         }
@@ -30,8 +31,13 @@ struct VPhoneLaunchpadNewMachineAdvancedView: View {
                     Picker("Mode", selection: $network) {
                         Text("NAT").tag("nat")
                         Text("Bridged").tag("bridged")
+                        Text("Tunnel").tag("tunnel")
                         Text("None").tag("none")
                     }
+                    if network == "tunnel" {
+                        Text("Traffic leaves through this Mac's own connections, so it follows the Mac's VPN.")
+                            .foregroundStyle(.secondary)
+                    }
                 }
 
                 patchSection