Allow returning from global search with the escape key

cmd+k jumps to the search tab but left users with no way back. Pressing
escape in the search field now returns to the tab they came from (never
into search itself).

Escape is handled at the search field's pressesBegan, alongside the
existing arrow-key navigation, since the focused UIKit field swallows
SwiftUI keyboard shortcuts.

ElementX/Sources/Application/Navigation/NavigationTabCoordinator.swift

@@ -100,7 +100,16 @@ import SwiftUI
     }
     
     /// The currently selected tab's tag.
-    var selectedTab: Tag?
+    var selectedTab: Tag? {
+        didSet {
+            if oldValue != selectedTab {
+                previousTab = oldValue
+            }
+        }
+    }
+    
+    /// The tab that was selected before the current one, used to return to it (e.g. cancelling search).
+    private(set) var previousTab: Tag?
     
     // MARK: Sheets
     

ElementX/Sources/FlowCoordinators/UserSessionFlowCoordinator.swift

@@ -229,6 +229,9 @@ class UserSessionFlowCoordinator: FlowCoordinatorProtocol {
                 switch action {
                 case .presentRoom(let roomID):
                     handleAppRoute(.room(roomID: roomID, via: []), animated: true)
+                case .cancel:
+                    // Return to the tab the user came from, but never back into search.
+                    navigationTabCoordinator.selectedTab = navigationTabCoordinator.previousTab == .search ? .chats : navigationTabCoordinator.previousTab ?? .chats
                 }
             }
             .store(in: &cancellables)

ElementX/Sources/Screens/SearchScreen/SearchScreenCoordinator.swift

@@ -15,6 +15,7 @@ struct SearchScreenCoordinatorParameters {
 
 enum SearchScreenCoordinatorAction {
     case presentRoom(roomID: String)
+    case cancel
 }
 
 final class SearchScreenCoordinator: CoordinatorProtocol {
@@ -38,6 +39,8 @@ final class SearchScreenCoordinator: CoordinatorProtocol {
             switch action {
             case .presentRoom(let roomID):
                 actionsSubject.send(.presentRoom(roomID: roomID))
+            case .cancel:
+                actionsSubject.send(.cancel)
             }
         }
         .store(in: &cancellables)

ElementX/Sources/Screens/SearchScreen/SearchScreenModels.swift

@@ -9,6 +9,7 @@ import Foundation
 
 enum SearchScreenViewModelAction {
     case presentRoom(roomID: String)
+    case cancel
 }
 
 struct SearchScreenViewState: BindableState {
@@ -29,6 +30,7 @@ enum SearchScreenViewAction {
     case selectRoom(roomID: String)
     case reachedTop
     case reachedBottom
+    case cancel
 }
 
 struct SearchScreenRoom: Identifiable, Equatable {

ElementX/Sources/Screens/SearchScreen/SearchScreenViewModel.swift

@@ -65,6 +65,8 @@ class SearchScreenViewModel: SearchScreenViewModelType, SearchScreenViewModelPro
             updateVisibleRange(edge: .top)
         case .reachedBottom:
             updateVisibleRange(edge: .bottom)
+        case .cancel:
+            actionsSubject.send(.cancel)
         }
     }
     

ElementX/Sources/Screens/SearchScreen/View/SearchScreen.swift

@@ -47,7 +47,8 @@ struct SearchScreen: View {
             }
         }
         .searchResultsKeyboardNavigation(moveUp: { moveSelection(backwards: true) },
-                                         moveDown: { moveSelection(backwards: false) })
+                                         moveDown: { moveSelection(backwards: false) },
+                                         cancel: { context.send(viewAction: .cancel) })
         // The TabView calls onAppear each time the search tab is selected, so the field re-focuses
         // and the selection resets on every switch.
         .onAppear {
@@ -189,12 +190,12 @@ private struct SearchScreenRoomCellButtonStyle: ButtonStyle {
 }
 
 private extension View {
-    /// Forwards hardware up/down arrow presses from the system search field to the given closures.
+    /// Forwards hardware up/down arrow and escape presses from the system search field to the given closures.
     ///
     /// The `.search` role tab owns its text field, so there's no SwiftUI hook for its key presses. We reach the
     /// field through the navigation stack (as ``SearchFieldStyle`` does) and swap its class for one that overrides
     /// `pressesBegan` — the same key interception the old global search performed on its own field.
-    func searchResultsKeyboardNavigation(moveUp: @escaping () -> Void, moveDown: @escaping () -> Void) -> some View {
+    func searchResultsKeyboardNavigation(moveUp: @escaping () -> Void, moveDown: @escaping () -> Void, cancel: @escaping () -> Void) -> some View {
         introspect(.navigationStack, on: .supportedVersions, scope: .ancestor) { navigationController in
             guard let textField = navigationController.navigationBar.topItem?.searchController?.searchBar.searchTextField else {
                 return
@@ -210,6 +211,8 @@ private extension View {
                     moveUp()
                 case .keyboardDownArrow:
                     moveDown()
+                case .keyboardEscape:
+                    cancel()
                 default:
                     return false
                 }

UnitTests/Sources/SearchScreenViewModelTests.swift

@@ -33,6 +33,8 @@ struct SearchScreenViewModelTests {
             switch action {
             case .presentRoom(let roomID):
                 roomID == "2"
+            case .cancel:
+                false
             }
         }
         
@@ -40,4 +42,20 @@ struct SearchScreenViewModelTests {
         
         try await deferred.fulfill()
     }
+    
+    @Test
+    func cancel() async throws {
+        let deferred = deferFulfillment(viewModel.actionsPublisher) { action in
+            switch action {
+            case .cancel:
+                true
+            default:
+                false
+            }
+        }
+        
+        context.send(viewAction: .cancel)
+        
+        try await deferred.fulfill()
+    }
 }