swift 6 fixes

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.6
+// swift-tools-version: 6.0
 
 import PackageDescription
 

Sources/SwiftTUI/Debug/log.swift

@@ -11,7 +11,7 @@ public func log(_ item: Any, terminator: String = "\n") {
     print(item, terminator: terminator, to: &logStream)
 }
 
-var logStream = LogStream()
+nonisolated(unsafe) var logStream = LogStream()
 
 struct LogStream: TextOutputStream {
     func write(_ string: String) {

Sources/SwiftTUI/Drawing/Edges.swift

@@ -1,6 +1,6 @@
 import Foundation
 
-public struct Edges: OptionSet {
+public struct Edges: OptionSet, Sendable {
     public let rawValue: UInt8
 
     public init(rawValue: UInt8) {

Sources/SwiftTUI/RunLoop/Application.swift

@@ -3,7 +3,7 @@ import Foundation
 import AppKit
 #endif
 
-public class Application {
+public class Application: @unchecked Sendable {
     private let node: Node
     private let window: Window
     private let control: Control
@@ -51,7 +51,7 @@ public class Application {
         #endif
     }
 
-    public func start() {
+    @MainActor public func start() {
         setInputMode()
         updateWindowSize()
         control.layout(size: window.layer.frame.size)

Sources/SwiftTUI/Views/Modifiers/OnAppear.swift

@@ -1,14 +1,14 @@
 import Foundation
 
 public extension View {
-    func onAppear(_ action: @escaping () -> Void) -> some View {
+    func onAppear(_ action: @escaping @Sendable () -> Void) -> some View {
         return OnAppear(content: self, action: action)
     }
 }
 
 private struct OnAppear<Content: View>: View, PrimitiveView, ModifierView {
     let content: Content
-    let action: () -> Void
+    let action: @Sendable () -> Void
 
     static var size: Int? { Content.size }
 
@@ -29,10 +29,10 @@ private struct OnAppear<Content: View>: View, PrimitiveView, ModifierView {
     }
 
     private class OnAppearControl: Control {
-        var action: () -> Void
+        var action: @Sendable () -> Void
         var didAppear = false
 
-        init(action: @escaping () -> Void) {
+        init(action: @escaping @Sendable () -> Void) {
             self.action = action
         }
 

Sources/SwiftTUI/Views/Stacks/Alignment.swift

@@ -1,18 +1,18 @@
 import Foundation
 
-public enum VerticalAlignment {
+public enum VerticalAlignment: Sendable {
     case top
     case center
     case bottom
 }
 
-public enum HorizontalAlignment {
+public enum HorizontalAlignment: Sendable {
     case leading
     case center
     case trailing
 }
 
-public struct Alignment {
+public struct Alignment: Sendable {
     public var horizontalAlignment: HorizontalAlignment
     public var verticalAlignment: VerticalAlignment