feat: multi-agent routing + multi-account providers

apps/macos/Sources/Clawdbot/CanvasA2UIActionMessageHandler.swift

@@ -79,14 +79,14 @@ final class CanvasA2UIActionMessageHandler: NSObject, WKScriptMessageHandler {
                 GatewayProcessManager.shared.setActive(true)
             }
 
-            let result = await GatewayConnection.shared.sendAgent(GatewayAgentInvocation(
-                message: text,
-                sessionKey: self.sessionKey,
-                thinking: "low",
-                deliver: false,
-                to: nil,
-                channel: .last,
-                idempotencyKey: actionId))
+	            let result = await GatewayConnection.shared.sendAgent(GatewayAgentInvocation(
+	                message: text,
+	                sessionKey: self.sessionKey,
+	                thinking: "low",
+	                deliver: false,
+	                to: nil,
+	                provider: .last,
+	                idempotencyKey: actionId))
 
             await MainActor.run {
                 guard let webView else { return }