Support Apple Remote Desktop auth via account username+password

RoyalVNCKit prioritizes .diffieHellman (ARD) over .vnc during handshake when
both are offered. My delegate adapter was passing an empty username to
VNCUsernamePasswordCredential, so any Mac with user-account screen sharing
enabled rejected the credential before .vnc fallback could happen.

Fix: persist a username on SavedConnection and pipe it through to the
credential callback. Leave blank to use the VNC-only password path.

AddConnection footer now explains the two Mac paths:
  • User account (ARD) — macOS short name + full account password
  • VNC-only password — blank username + ≤8 char password

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Packages/VNCCore/Sources/VNCCore/Session/SessionController.swift

@@ -28,6 +28,7 @@ public final class SessionController {
     public let displayName: String
     public let host: String
     public let port: Int
+    public let username: String
 
     private let keychainTag: String
     private let passwordProvider: any PasswordProviding
@@ -47,6 +48,7 @@ public final class SessionController {
         displayName: String,
         host: String,
         port: Int,
+        username: String = "",
         keychainTag: String,
         viewOnly: Bool = false,
         clipboardSyncEnabled: Bool = true,
@@ -59,6 +61,7 @@ public final class SessionController {
         self.displayName = displayName
         self.host = host
         self.port = port
+        self.username = username
         self.keychainTag = keychainTag
         self.viewOnly = viewOnly
         self.clipboardSyncEnabled = clipboardSyncEnabled
@@ -78,6 +81,7 @@ public final class SessionController {
             displayName: saved.displayName,
             host: saved.host,
             port: saved.port,
+            username: saved.username,
             keychainTag: saved.keychainTag,
             viewOnly: saved.viewOnly,
             clipboardSyncEnabled: saved.clipboardSyncEnabled,
@@ -302,7 +306,8 @@ public final class SessionController {
         let adapter = DelegateAdapter(
             controller: self,
             passwordProvider: passwordProvider,
-            keychainTag: keychainTag
+            keychainTag: keychainTag,
+            username: username
         )
         connection.delegate = adapter
         self.connection = connection
@@ -366,13 +371,16 @@ private final class DelegateAdapter: NSObject, VNCConnectionDelegate, @unchecked
     weak var controller: SessionController?
     let passwordProvider: any PasswordProviding
     let keychainTag: String
+    let username: String
 
     init(controller: SessionController,
          passwordProvider: any PasswordProviding,
-         keychainTag: String) {
+         keychainTag: String,
+         username: String) {
         self.controller = controller
         self.passwordProvider = passwordProvider
         self.keychainTag = keychainTag
+        self.username = username
     }
 
     func connection(_ connection: VNCConnection,
@@ -398,7 +406,7 @@ private final class DelegateAdapter: NSObject, VNCConnectionDelegate, @unchecked
         case .vnc:
             credential = VNCPasswordCredential(password: pwd)
         case .appleRemoteDesktop, .ultraVNCMSLogonII:
-            credential = VNCUsernamePasswordCredential(username: "", password: pwd)
+            credential = VNCUsernamePasswordCredential(username: username, password: pwd)
         @unknown default:
             credential = VNCPasswordCredential(password: pwd)
         }

Packages/VNCCore/Sources/VNCCore/Storage/SavedConnection.swift

@@ -7,6 +7,7 @@ public final class SavedConnection {
     public var displayName: String
     public var host: String
     public var port: Int
+    public var username: String
     public var colorTagRaw: String
     public var lastConnectedAt: Date?
     public var preferredEncodings: [String]
@@ -23,6 +24,7 @@ public final class SavedConnection {
         displayName: String,
         host: String,
         port: Int = 5900,
+        username: String = "",
         colorTag: ColorTag = .blue,
         preferredEncodings: [String] = ["7", "16", "5", "6"],
         keychainTag: String = UUID().uuidString,
@@ -37,6 +39,7 @@ public final class SavedConnection {
         self.displayName = displayName
         self.host = host
         self.port = port
+        self.username = username
         self.colorTagRaw = colorTag.rawValue
         self.lastConnectedAt = nil
         self.preferredEncodings = preferredEncodings