refactor: replace hacks with native macOS patterns and clean up concurrency (#830)

* refactor: replace hacks with native macOS patterns and clean up concurrency

- Toolbar: replace opacity/hitTesting hacks with conditional rendering for
  database switcher, import button, and results button; merge connection +
  database into single toolbar item group
- Toolbar: hide "Switch Database" hint in empty state for non-switching databases
- SSH: replace DispatchSemaphore blocking with DispatchQueue.main.sync in
  PromptPassphraseProvider and PromptTOTPProvider
- Terminal: replace @State NSObjectProtocol observer with .task async
  notification stream for tunnel waiting
- Concurrency: remove redundant Task { @mainactor in } across 28 files where
  enclosing type is already @mainactor; keep @mainactor in @sendable closures
- Replace DispatchQueue.main.asyncAfter with Task.sleep in MCPSection and
  FavoritesSidebarViewModel

* fix: restore required @mainactor in actor and @sendable closure contexts

Author: datlechin

TablePro/AppDelegate+ConnectionHandler.swift

@@ -84,7 +84,7 @@ extension AppDelegate {
         connectingURLConnectionIds.insert(connection.id)
         connectingURLParamKeys.insert(paramKey)
 
-        Task { @MainActor in
+        Task {
             defer {
                 self.connectingURLConnectionIds.remove(connection.id)
                 self.connectingURLParamKeys.remove(paramKey)
@@ -136,7 +136,7 @@ extension AppDelegate {
         guard !connectingFilePaths.contains(filePath) else { return }
         connectingFilePaths.insert(filePath)
 
-        Task { @MainActor in
+        Task {
             defer {
                 self.connectingFilePaths.remove(filePath)
             }
@@ -186,7 +186,7 @@ extension AppDelegate {
         guard !connectingFilePaths.contains(filePath) else { return }
         connectingFilePaths.insert(filePath)
 
-        Task { @MainActor in
+        Task {
             defer {
                 self.connectingFilePaths.remove(filePath)
             }
@@ -236,7 +236,7 @@ extension AppDelegate {
         guard !connectingFilePaths.contains(filePath) else { return }
         connectingFilePaths.insert(filePath)
 
-        Task { @MainActor in
+        Task {
             defer {
                 self.connectingFilePaths.remove(filePath)
             }
@@ -311,7 +311,7 @@ extension AppDelegate {
     }
 
     private func postSQLFilesWhenReady(urls: [URL]) {
-        Task { @MainActor in
+        Task {
             await waitForConnection(timeout: .seconds(3))
             NotificationCenter.default.post(name: .openSQLFiles, object: urls)
         }
@@ -331,7 +331,7 @@ extension AppDelegate {
     // MARK: - Post-Connect Actions
 
     private func handlePostConnectionActions(_ parsed: ParsedConnectionURL, connectionId: UUID) {
-        Task { @MainActor in
+        Task {
             await waitForConnection(timeout: .seconds(5))
 
             if let schema = parsed.schema {
@@ -409,7 +409,7 @@ extension AppDelegate {
                 continuation.resume()
             }
 
-            let timeoutTask = Task { @MainActor in
+            let timeoutTask = Task {
                 try? await Task.sleep(for: timeout)
                 resumeOnce()
             }
@@ -438,7 +438,7 @@ extension AppDelegate {
                 continuation.resume()
             }
 
-            let timeoutTask = Task { @MainActor in
+            let timeoutTask = Task {
                 try? await Task.sleep(for: timeout)
                 resumeOnce()
             }

TablePro/AppDelegate+FileOpen.swift

@@ -48,7 +48,7 @@ extension AppDelegate {
         let initialPayload = EditorTabPayload(connectionId: connectionId)
         WindowManager.shared.openTab(payload: initialPayload)
 
-        Task { @MainActor in
+        Task {
             do {
                 try await DatabaseManager.shared.connectToSession(connection)
                 for window in NSApp.windows where self.isWelcomeWindow(window) {
@@ -88,22 +88,22 @@ extension AppDelegate {
     func handleOpenURLs(_ urls: [URL]) {
         let deeplinks = urls.filter { $0.scheme == "tablepro" }
         if !deeplinks.isEmpty {
-            Task { @MainActor in
+            Task {
                 for url in deeplinks { await self.handleDeeplink(url) }
             }
         }
 
         let plugins = urls.filter { $0.pathExtension == "tableplugin" }
         if !plugins.isEmpty {
-            Task { @MainActor in
+            Task {
                 for url in plugins { await self.handlePluginInstall(url) }
             }
         }
 
         let databaseURLs = urls.filter { isDatabaseURL($0) }
         if !databaseURLs.isEmpty {
             suppressWelcomeWindow()
-            Task { @MainActor in
+            Task {
                 for url in databaseURLs { self.handleDatabaseURL(url) }
                 // endFileOpenSuppression is called here to match suppressWelcomeWindow above.
                 // Individual handlers no longer manage this flag.
@@ -114,7 +114,7 @@ extension AppDelegate {
         let databaseFiles = urls.filter { isDatabaseFile($0) }
         if !databaseFiles.isEmpty {
             suppressWelcomeWindow()
-            Task { @MainActor in
+            Task {
                 for url in databaseFiles {
                     guard let dbType = self.databaseTypeForFile(url) else { continue }
                     switch dbType {
@@ -245,7 +245,7 @@ extension AppDelegate {
         let deeplinkPayload = EditorTabPayload(connectionId: connection.id)
         WindowManager.shared.openTab(payload: deeplinkPayload)
 
-        Task { @MainActor in
+        Task {
             do {
                 // Confirm pre-connect script if present (deep links are external, so always confirm)
                 if let script = connection.preConnectScript,

TablePro/AppDelegate+WindowConfig.swift

@@ -86,7 +86,7 @@ extension AppDelegate {
         let payload = EditorTabPayload(connectionId: connection.id, intent: .restoreOrDefault)
         WindowManager.shared.openTab(payload: payload)
 
-        Task { @MainActor in
+        Task {
             do {
                 try await DatabaseManager.shared.connectToSession(connection)
 

TablePro/AppDelegate.swift

@@ -99,7 +99,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         PluginManager.shared.loadPlugins()
         ConnectionStorage.shared.migratePluginSecureFieldsIfNeeded()
 
-        Task { @MainActor in
+        Task {
             LicenseManager.shared.startPeriodicValidation()
         }
 
@@ -176,7 +176,7 @@ class AppDelegate: NSObject, NSApplicationDelegate {
         guard let rejected = notification.object as? [(name: String, reason: String)],
               !rejected.isEmpty else { return }
         let details = rejected.map { "\($0.name): \($0.reason)" }.joined(separator: "\n")
-        Task { @MainActor in
+        Task {
             let alert = NSAlert()
             alert.messageText = String(
                 format: String(localized: "%d plugin(s) could not be loaded"),

TablePro/Core/AI/InlineSuggestionManager.swift

@@ -191,7 +191,7 @@ final class InlineSuggestionManager {
         generationID &+= 1
         let myGeneration = generationID
 
-        currentTask = Task { [weak self] in
+        currentTask = Task { @MainActor [weak self] in
             guard let self else { return }
             self.suggestionOffset = cursorOffset
 

TablePro/Core/SSH/Auth/PromptPassphraseProvider.swift

@@ -26,16 +26,7 @@ internal final class PromptPassphraseProvider: @unchecked Sendable {
         if Thread.isMainThread {
             return showAlert()
         }
-
-        let semaphore = DispatchSemaphore(value: 0)
-        var result: PassphrasePromptResult?
-        DispatchQueue.main.async {
-            result = self.showAlert()
-            semaphore.signal()
-        }
-        let waitResult = semaphore.wait(timeout: .now() + 120)
-        guard waitResult == .success else { return nil }
-        return result
+        return DispatchQueue.main.sync { showAlert() }
     }
 
     private func showAlert() -> PassphrasePromptResult? {

TablePro/Core/SSH/Auth/PromptTOTPProvider.swift

@@ -15,18 +15,7 @@ internal final class PromptTOTPProvider: TOTPProvider, @unchecked Sendable {
         if Thread.isMainThread {
             return try handleResult(showAlert())
         }
-
-        let semaphore = DispatchSemaphore(value: 0)
-        var code: String?
-        DispatchQueue.main.async {
-            code = self.showAlert()
-            semaphore.signal()
-        }
-        let result = semaphore.wait(timeout: .now() + 120)
-        guard result == .success else {
-            throw SSHTunnelError.connectionTimeout
-        }
-        return try handleResult(code)
+        return try handleResult(DispatchQueue.main.sync { showAlert() })
     }
 
     // Note: runModal() is intentional here. This method runs on the main thread

TablePro/Core/Services/Infrastructure/MainSplitViewController.swift

@@ -411,7 +411,7 @@ internal final class MainSplitViewController: NSSplitViewController, InspectorVi
             },
             set: { [weak self] newValue in
                 guard let sessionId = self?.payload?.connectionId ?? self?.currentSession?.id else { return }
-                Task { @MainActor in
+                Task {
                     DatabaseManager.shared.updateSession(sessionId) { session in
                         set(&session, newValue)
                     }

TablePro/Core/Services/Infrastructure/MainWindowToolbar.swift

@@ -81,8 +81,7 @@ internal final class MainWindowToolbar: NSObject, NSToolbarDelegate {
 
     // MARK: - Identifiers
 
-    private static let connection = NSToolbarItem.Identifier("com.TablePro.toolbar.connection")
-    private static let database = NSToolbarItem.Identifier("com.TablePro.toolbar.database")
+    private static let connectionGroup = NSToolbarItem.Identifier("com.TablePro.toolbar.connectionGroup")
     private static let refresh = NSToolbarItem.Identifier("com.TablePro.toolbar.refresh")
     private static let saveChanges = NSToolbarItem.Identifier("com.TablePro.toolbar.saveChanges")
     private static let principal = NSToolbarItem.Identifier("com.TablePro.toolbar.principal")
@@ -106,8 +105,7 @@ internal final class MainWindowToolbar: NSObject, NSToolbarDelegate {
         [
             Self.sidebarToggle,
             .sidebarTrackingSeparator,
-            Self.connection,
-            Self.database,
+            Self.connectionGroup,
             Self.refreshSaveGroup,
             .flexibleSpace,
             Self.principal,
@@ -150,12 +148,12 @@ internal final class MainWindowToolbar: NSObject, NSToolbarDelegate {
         switch itemIdentifier {
         case Self.sidebarToggle:
             return makeSidebarToggleItem(coordinator: coordinator)
-        case Self.connection:
+        case Self.connectionGroup:
             return hostingItem(id: itemIdentifier, label: String(localized: "Connection"),
-                               content: ConnectionToolbarButton(coordinator: coordinator))
-        case Self.database:
-            return hostingItem(id: itemIdentifier, label: String(localized: "Database"),
-                               content: DatabaseToolbarButton(coordinator: coordinator))
+                               content: HStack(spacing: 4) {
+                                   ConnectionToolbarButton(coordinator: coordinator)
+                                   DatabaseToolbarButton(coordinator: coordinator)
+                               })
         case Self.refresh:
             return hostingItem(id: itemIdentifier, label: String(localized: "Refresh"),
                                content: RefreshToolbarButton(coordinator: coordinator))
@@ -283,19 +281,18 @@ private struct DatabaseToolbarButton: View {
     var body: some View {
         let state = coordinator.toolbarState
         let supportsSwitch = PluginManager.shared.supportsDatabaseSwitching(for: state.databaseType)
-        Button {
-            coordinator.commandActions?.openDatabaseSwitcher()
-        } label: {
-            Label("Database", systemImage: "cylinder")
+        if supportsSwitch {
+            Button {
+                coordinator.commandActions?.openDatabaseSwitcher()
+            } label: {
+                Label("Database", systemImage: "cylinder")
+            }
+            .help(String(localized: "Open Database (⌘K)"))
+            .disabled(
+                state.connectionState != .connected
+                    || PluginManager.shared.connectionMode(for: state.databaseType) == .fileBased
+            )
         }
-        .help(String(localized: "Open Database (⌘K)"))
-        .disabled(
-            !supportsSwitch
-                || state.connectionState != .connected
-                || PluginManager.shared.connectionMode(for: state.databaseType) == .fileBased
-        )
-        .opacity(supportsSwitch ? 1 : 0)
-        .allowsHitTesting(supportsSwitch)
     }
 }
 
@@ -415,20 +412,20 @@ private struct ResultsToolbarButton: View {
 
     var body: some View {
         let state = coordinator.toolbarState
-        Button {
-            coordinator.commandActions?.toggleResults()
-        } label: {
-            Label(
-                "Results",
-                systemImage: state.isResultsCollapsed
-                    ? "rectangle.bottomhalf.inset.filled"
-                    : "rectangle.inset.filled"
-            )
+        if !state.isTableTab {
+            Button {
+                coordinator.commandActions?.toggleResults()
+            } label: {
+                Label(
+                    "Results",
+                    systemImage: state.isResultsCollapsed
+                        ? "rectangle.bottomhalf.inset.filled"
+                        : "rectangle.inset.filled"
+                )
+            }
+            .help(String(localized: "Toggle Results (⌘⌥R)"))
+            .disabled(state.connectionState != .connected)
         }
-        .help(String(localized: "Toggle Results (⌘⌥R)"))
-        .disabled(state.connectionState != .connected)
-        .opacity(state.isTableTab ? 0 : 1)
-        .allowsHitTesting(!state.isTableTab)
     }
 }
 
@@ -496,20 +493,18 @@ private struct ImportToolbarButton: View {
 
     var body: some View {
         let state = coordinator.toolbarState
-        let supportsImport = PluginManager.shared.supportsImport(for: state.databaseType)
-        Button {
-            coordinator.commandActions?.importTables()
-        } label: {
-            Label("Import", systemImage: "square.and.arrow.down")
+        if PluginManager.shared.supportsImport(for: state.databaseType) {
+            Button {
+                coordinator.commandActions?.importTables()
+            } label: {
+                Label("Import", systemImage: "square.and.arrow.down")
+            }
+            .help(String(localized: "Import Data (⌘⇧I)"))
+            .disabled(
+                state.connectionState != .connected
+                    || state.safeModeLevel.blocksAllWrites
+            )
         }
-        .help(String(localized: "Import Data (⌘⇧I)"))
-        .disabled(
-            state.connectionState != .connected
-                || state.safeModeLevel.blocksAllWrites
-                || !supportsImport
-        )
-        .opacity(supportsImport ? 1 : 0)
-        .allowsHitTesting(supportsImport)
     }
 }
 

TablePro/Core/Services/Query/SchemaProviderRegistry.swift

@@ -49,7 +49,7 @@ final class SchemaProviderRegistry {
         count -= 1
         if count <= 0 {
             refCounts.removeValue(forKey: connectionId)
-            removalTasks[connectionId] = Task { @MainActor in
+            removalTasks[connectionId] = Task {
                 try? await Task.sleep(nanoseconds: 5_000_000_000)
                 guard !Task.isCancelled else { return }
                 self.providers.removeValue(forKey: connectionId)