Fix the Swift translations in the AIT guides

Translated using the translate-examples-to-swift skill in the
as-yet-unmerged PR #3192. I've reviewed them.

Author: lawrence-forooghian

src/pages/docs/guides/ai-transport/anthropic-message-per-response.mdx

@@ -628,6 +628,14 @@ await channel.subscribe((message) => {
 console.log('Subscriber ready, waiting for tokens...');
 ```
 
+{/* Swift example test harness
+ID: anthropic-message-per-response-1
+To verify: copy this comment into a Swift file, paste the example code into the function body, run `swift build`
+
+@MainActor
+func example_anthropic_message_per_response_1() async throws {
+    // --- example code starts here ---
+*/}
 ```client_swift
 import Ably
 
@@ -640,37 +648,48 @@ let channel = realtime.channels.get("ai:{{RANDOM_CHANNEL_NAME}}")
 // Track responses by message serial
 var responses: [String: String] = [:]
 
-// Subscribe to receive messages
-channel.subscribe { message in
-    guard let serial = message.serial else { return }
-
-    switch message.action {
-    case .create:
-        // New response started
-        print("\n[Response started] \(serial)")
-        responses[serial] = message.data as? String ?? ""
-
-    case .messageAppend:
-        // Append token to existing response
-        let current = responses[serial] ?? ""
-        let token = message.data as? String ?? ""
-        responses[serial] = current + token
-
-        // Display token as it arrives
-        print(token, terminator: "")
-
-    case .update:
-        // Replace entire response content
-        responses[serial] = message.data as? String ?? ""
-        print("\n[Response updated with full content]")
-
-    default:
-        break
-    }
+// Subscribe to receive messages and wait for the channel to attach
+try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, any Error>) in
+    channel.subscribe(attachCallback: { error in
+        if let error {
+            continuation.resume(throwing: error)
+        } else {
+            continuation.resume()
+        }
+    }, callback: { message in
+        MainActor.assumeIsolated {
+            guard let serial = message.serial else { return }
+            guard let data = message.data as? String else { return }
+
+            switch message.action {
+            case .create:
+                // New response started
+                print("\n[Response started] \(serial)")
+                responses[serial] = data
+
+            case .append:
+                // Append token to existing response
+                let current = responses[serial] ?? ""
+                responses[serial] = current + data
+
+                // Display token as it arrives
+                print(data, terminator: "")
+
+            case .update:
+                // Replace entire response content
+                responses[serial] = data
+                print("\n[Response updated with full content]")
+
+            default:
+                break
+            }
+        }
+    })
 }
 
 print("Subscriber ready, waiting for tokens...")
 ```
+{/* --- end example code --- */}
 
 ```client_java
 import io.ably.lib.realtime.AblyRealtime;
@@ -909,6 +928,14 @@ await channel.subscribe((message) => {
 });
 ```
 
+{/* Swift example test harness
+ID: anthropic-message-per-response-2
+To verify: copy this comment into a Swift file, paste the example code into the function body, run `swift build`
+
+@MainActor
+func example_anthropic_message_per_response_2(realtime: ARTRealtime) async throws {
+    // --- example code starts here ---
+*/}
 ```client_swift
 // Use rewind to receive recent historical messages
 let channelOptions = ARTRealtimeChannelOptions()
@@ -918,29 +945,41 @@ let channel = realtime.channels.get("ai:{{RANDOM_CHANNEL_NAME}}", options: chann
 
 var responses: [String: String] = [:]
 
-channel.subscribe { message in
-    guard let serial = message.serial else { return }
-
-    switch message.action {
-    case .create:
-        responses[serial] = message.data as? String ?? ""
-
-    case .messageAppend:
-        let current = responses[serial] ?? ""
-        let token = message.data as? String ?? ""
-        responses[serial] = current + token
-        print(token, terminator: "")
-
-    case .update:
-        // Historical messages contain full concatenated response
-        responses[serial] = message.data as? String ?? ""
-        print("\n[Historical response]: \(responses[serial] ?? "")")
-
-    default:
-        break
-    }
+// Subscribe and wait for the channel to attach
+try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, any Error>) in
+    channel.subscribe(attachCallback: { error in
+        if let error {
+            continuation.resume(throwing: error)
+        } else {
+            continuation.resume()
+        }
+    }, callback: { message in
+        MainActor.assumeIsolated {
+            guard let serial = message.serial else { return }
+            guard let data = message.data as? String else { return }
+
+            switch message.action {
+            case .create:
+                responses[serial] = data
+
+            case .append:
+                let current = responses[serial] ?? ""
+                responses[serial] = current + data
+                print(data, terminator: "")
+
+            case .update:
+                // Historical messages contain full concatenated response
+                responses[serial] = data
+                print("\n[Historical response]: \(responses[serial] ?? "")")
+
+            default:
+                break
+            }
+        }
+    })
 }
 ```
+{/* --- end example code --- */}
 
 ```client_java
 import io.ably.lib.realtime.AblyRealtime;

src/pages/docs/guides/ai-transport/anthropic-message-per-token.mdx

@@ -613,6 +613,14 @@ await channel.subscribe('stop', (message) => {
 console.log('Subscriber ready, waiting for tokens...');
 ```
 
+{/* Swift example test harness
+ID: anthropic-message-per-token-1
+To verify: copy this comment into a Swift file, paste the example code into the function body, run `swift build`
+
+@MainActor
+func example_anthropic_message_per_token_1() async throws {
+    // --- example code starts here ---
+*/}
 ```client_swift
 import Ably
 
@@ -625,34 +633,52 @@ let channel = realtime.channels.get("{{RANDOM_CHANNEL_NAME}}")
 // Track responses by ID
 var responses: [String: String] = [:]
 
-// Handle response start
-channel.subscribe("start") { message in
-    guard let responseId = message.extras?.headers?["responseId"] as? String else { return }
-    print("\n[Response started] \(responseId)")
-    responses[responseId] = ""
-}
-
-// Handle tokens
-channel.subscribe("token") { message in
-    guard let responseId = message.extras?.headers?["responseId"] as? String,
-          let token = message.data as? String else { return }
-
-    // Append token to response
-    responses[responseId, default: ""] += token
-
-    // Display token as it arrives
-    print(token, terminator: "")
-}
-
-// Handle response stop
-channel.subscribe("stop") { message in
-    guard let responseId = message.extras?.headers?["responseId"] as? String else { return }
-    let finalText = responses[responseId] ?? ""
-    print("\n[Response completed] \(responseId)")
+// Subscribe to all events and handle by message name
+try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, any Error>) in
+    channel.subscribe(attachCallback: { error in
+        if let error {
+            continuation.resume(throwing: error)
+        } else {
+            continuation.resume()
+        }
+    }) { message in
+        MainActor.assumeIsolated {
+            guard let extras = (try? message.extras?.toJSON()) as? [String: Any],
+                  let headers = extras["headers"] as? [String: Any],
+                  let responseID = headers["responseId"] as? String else { return }
+
+            switch message.name {
+            case "start":
+                // Handle response start
+                print("\n[Response started] \(responseID)")
+                responses[responseID] = ""
+
+            case "token":
+                // Handle tokens
+                guard let token = message.data as? String else { return }
+
+                // Append token to response
+                let currentText = responses[responseID] ?? ""
+                responses[responseID] = currentText + token
+
+                // Display token as it arrives
+                print(token, terminator: "")
+
+            case "stop":
+                // Handle response stop
+                let finalText = responses[responseID]
+                print("\n[Response completed] \(responseID)")
+
+            default:
+                break
+            }
+        }
+    }
 }
 
 print("Subscriber ready, waiting for tokens...")
 ```
+{/* --- end example code --- */}
 
 ```client_java
 import io.ably.lib.realtime.AblyRealtime;