fix: Pre-iOS 18 crash on queue isolation

Author: plajdo

Sources/GoodNetworking/Session/DataTaskProxy.swift

@@ -54,12 +54,14 @@ import Foundation
             self.receivedError = URLError(.unknown)
         }
 
-        logger.logNetworkEvent(
-            message: prepareRequestInfo(),
-            level: receivedError == nil ? .debug : .warning,
-            file: #file,
-            line: #line
-        )
+        Task { @NetworkActor in
+            logger.logNetworkEvent(
+                message: prepareRequestInfo(),
+                level: receivedError == nil ? .debug : .warning,
+                file: #file,
+                line: #line
+            )
+        }
 
         continuation?.resume()
         continuation = nil

Sources/GoodNetworking/Session/NetworkSession.swift

@@ -67,7 +67,7 @@ import Foundation
         self.configuration = configuration
         self.delegateQueue = operationQueue
 
-        // create URLSession lazily, isolated on @NetworkActor, when requested first time
+        // create URLSession lazily, isolated to @NetworkActor, when requested first time
 
         super.init()
     }

Sources/GoodNetworking/Utilities/NetworkActor.swift

@@ -18,8 +18,6 @@ import Foundation
 
     private static let executor: NetworkActorExecutor = NetworkActorExecutor()
 
-    // MARK: - Properties
-    
     // MARK: - Computed properties
 
     public nonisolated var unownedExecutor: UnownedSerialExecutor {
@@ -37,9 +35,15 @@ import Foundation
     ) rethrows -> sending T {
         typealias YesActor = @NetworkActor () throws -> sending T
         typealias NoActor = () throws -> sending T
-        
-        NetworkActor.preconditionIsolated()
-        
+
+        if #available(iOS 18, *) {
+            NetworkActor.preconditionIsolated()
+        } else {
+            // manual call to checkIsolated() as Swift runtime doesn't
+            // support custom implementation before iOS 18/26
+            executor.checkIsolated()
+        }
+
         return try withoutActuallyEscaping(block) { (_ fn: @escaping YesActor) throws -> sending T in
             try unsafeBitCast(fn, to: NoActor.self)()
         }