Support the Xcode 26 toolchain

TCA 1.16.1 does not compile under Swift 6.3, so moving to the new
toolchain forces a matching dependency bump.

- Upgrade swift-composable-architecture from 1.16.1 to 1.26.2 and
  adopt the new Shared(value:) signature
- Align the Tool and ChatPlugins package platforms to macOS 13, so
  they match every target in the project
- Declare the missing CommandHandler dependency in SuggestionWidget,
  which was breaking the test bundle link step
- Drop stale entries from Package.resolved

Claude-Session: https://claude.ai/code/session_01QrUJLx9ppwpa2DFUoSGUYo

Author: JayDaniel

ChatPlugins/Package.swift

@@ -5,7 +5,7 @@ import PackageDescription
 
 let package = Package(
     name: "ChatPlugins",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .library(
             name: "ChatPlugins",

Copilot for Xcode.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -46,7 +46,7 @@ let package = Package(
         .package(url: "https://github.com/pointfreeco/swift-dependencies", from: "1.0.0"),
         .package(
             url: "https://github.com/pointfreeco/swift-composable-architecture",
-            exact: "1.16.1"
+            exact: "1.26.2"
         ),
         // quick hack to support custom UserDefaults
         // https://github.com/sindresorhus/KeyboardShortcuts
@@ -233,6 +233,7 @@ let package = Package(
                 .product(name: "Logger", package: "Tool"),
                 .product(name: "CustomAsyncAlgorithms", package: "Tool"),
                 .product(name: "CodeDiff", package: "Tool"),
+                .product(name: "CommandHandler", package: "Tool"),
                 .product(name: "AsyncAlgorithms", package: "swift-async-algorithms"),
                 .product(name: "MarkdownUI", package: "swift-markdown-ui"),
                 .product(name: "ComposableArchitecture", package: "swift-composable-architecture"),

Core/Package.swift

@@ -471,7 +471,7 @@ extension WindowBaseCommandHandler {
 
         _ = await MainActor.run {
             store.send(.promptToCodeGroup(.activateOrCreatePromptToCode(.init(
-                promptToCodeState: Shared(.init(
+                promptToCodeState: Shared(value: .init(
                     source: .init(
                         language: codeLanguage,
                         documentURL: fileURL,

Core/Sources/Service/SuggestionCommandHandler/WindowBaseCommandHandler.swift

@@ -1082,7 +1082,7 @@ extension PromptToCodePanelView {
 
 #Preview("Multiple Snippets") {
     PromptToCodePanelView(store: .init(initialState: .init(
-        promptToCodeState: Shared(ModificationState(
+        promptToCodeState: Shared(value: ModificationState(
             source: .init(
                 language: CodeLanguage.builtIn(.swift),
                 documentURL: URL(
@@ -1164,7 +1164,7 @@ extension PromptToCodePanelView {
 
 #Preview("Detached With Long File Name") {
     PromptToCodePanelView(store: .init(initialState: .init(
-        promptToCodeState: Shared(ModificationState(
+        promptToCodeState: Shared(value: ModificationState(
             source: .init(
                 language: CodeLanguage.builtIn(.swift),
                 documentURL: URL(
@@ -1219,7 +1219,7 @@ extension PromptToCodePanelView {
 
 #Preview("Generating") {
     PromptToCodePanelView(store: .init(initialState: .init(
-        promptToCodeState: Shared(ModificationState(
+        promptToCodeState: Shared(value: ModificationState(
             source: .init(
                 language: CodeLanguage.builtIn(.swift),
                 documentURL: URL(

Core/Sources/SuggestionWidget/SuggestionPanelContent/PromptToCodePanelView.swift

@@ -5,7 +5,7 @@ import PackageDescription
 
 let package = Package(
     name: "Tool",
-    platforms: [.macOS(.v12)],
+    platforms: [.macOS(.v13)],
     products: [
         .library(name: "XPCShared", targets: ["XPCShared"]),
         .library(name: "Terminal", targets: ["Terminal"]),
@@ -73,7 +73,7 @@ let package = Package(
         .package(url: "https://github.com/intitni/Highlightr", branch: "master"),
         .package(
             url: "https://github.com/pointfreeco/swift-composable-architecture",
-            exact: "1.16.1"
+            exact: "1.26.2"
         ),
         .package(url: "https://github.com/apple/swift-syntax.git", from: "600.0.0"),
         .package(url: "https://github.com/GottaGetSwifty/CodableWrappers", from: "2.0.7"),