fix(macos): validate remote ports

apps/macos/Sources/Clawdbot/GatewayAgentChannel.swift

@@ -0,0 +1,27 @@
+import Foundation
+
+enum GatewayAgentChannel: String, CaseIterable, Sendable {
+    case last
+    case webchat
+    case whatsapp
+    case telegram
+
+    init(raw: String?) {
+        let trimmed = raw?
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+            .lowercased() ?? ""
+        self = GatewayAgentChannel(rawValue: trimmed) ?? .last
+    }
+
+    func shouldDeliver(_ isLast: Bool) -> Bool {
+        switch self {
+        case .webchat:
+            return false
+        case .last:
+            return isLast
+        case .whatsapp, .telegram:
+            return true
+        }
+    }
+}
+