Finish migration of UnitTests target from XCTestCase to Swift Testing (#5129)

* Initial plan

* Migrate 3 test files from XCTest to Swift Testing

- MediaUploadPreviewScreenViewModelTests: @MainActor @Suite struct with init(),
  BundleFinder class for Bundle(for:), mutating test/setup functions,
  [self] capture replacing [weak self] in closures
- NotificationManagerTests: @MainActor @Suite final class with init()/deinit,
  expectation/fulfillment(of:) replaced with confirmation(...), test_ prefix stripped
- NotificationSettingsScreenViewModelTests: @MainActor @Suite struct with
  init() throws, non-optional stored properties, test prefix stripped

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate 3 XCTest files to Swift Testing

- NotificationSettingsEditScreenViewModelTests: @MainActor @Suite struct with init() throws, mutating test methods
- TimelineViewModelTests: @MainActor @Suite final class with init() async throws + deinit
- AttributedStringBuilderTests: @Suite struct with init() async throws

All XCT assertions replaced with #expect/#require/Issue.record

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate 4 test files from XCTest to Swift Testing

- TimelineMediaPreviewViewModelTests: @Suite struct, mutating @Test funcs,
  testLoadingItem renamed to loadingItem (called internally by other tests)
- ServerConfirmationScreenViewModelTests: @Suite final class with init()/deinit
- CompletionSuggestionServiceTests: @Suite struct with init()
- RoomFlowCoordinatorTests: @Suite final class with deinit

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate 4 test files from XCTest to Swift Testing

- VoiceMessageRecorderTests: @Suite struct with init() async throws,
  added BundleFinder class for Bundle lookup, migrated all assertions
- SpaceScreenViewModelTests: @Suite struct, private mutating setupViewModel,
  all test funcs mutating, XCTestExpectation → confirmation
- RoomNotificationSettingsScreenViewModelTests: @Suite struct with
  init() throws, cancellable tests marked mutating
- JoinRoomScreenViewModelTests: @Suite final class with init()/deinit,
  XCTestExpectation → confirmation

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate 6 test files from XCTestCase to Swift Testing

Co-authored-by: pixlwave <6060466+pixlwave@users.noreply.github.com>

* Fix trailing blank line in RoomPollsHistoryScreenViewModelTests

Co-authored-by: pixlwave <6060466+pixlwave@users.noreply.github.com>

* Migrate 3 test files from XCTest to Swift Testing

- MediaUploadingPreprocessorTests: @Suite final class with init()/deinit,
  removed executionTimeAllowance, XCTAssertEqual(accuracy:) → abs(Double)
- SecurityAndPrivacyScreenViewModelTests: @MainActor @Suite final class,
  5 expectation+fulfillment → await confirmation(...)
- CreateRoomViewModelTests: @MainActor @Suite final class,
  4 expectation+fulfillment → await confirmation(...)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate RoomScreenViewModelTests and RoomDetailsScreenViewModelTests to Swift Testing

- Replace XCTest with Testing framework
- RoomScreenViewModelTests: final class with init() async throws + deinit
- RoomDetailsScreenViewModelTests: struct with init() and mutating funcs
- Convert XCT assertions to #expect / Issue.record
- Convert XCTestExpectation patterns to confirmation { confirm in }
- Strip 'test' prefix from all test function names

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Migrate ComposerToolbarViewModelTests from XCTest to Swift Testing

- Replace import XCTest with import Testing
- Convert XCTestCase class to @MainActor @Suite final class
- Replace setUp()/tearDown() with init()/deinit
- Strip 'test' prefix from all 41 test method names and add @Test
- Replace XCTAssert* with #expect()/#require()
- Replace try XCTUnwrap() with try #require()
- Convert expectation+wait patterns to deferFulfillment with PassthroughSubject
- Convert isInverted expectation to boolean flag checked after await
- Use deferFulfillment on $viewState for state-transition tests

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Address comments with Copilot.

* Fix the failing tests.

* Fixed flaky tests (#5137)

resolved flaky tests

* Tweaks and fixes.

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Co-authored-by: pixlwave <6060466+pixlwave@users.noreply.github.com>
Co-authored-by: Doug <douglase@element.io>
Co-authored-by: Mauro <34335419+Velin92@users.noreply.github.com>

UnitTests/Sources/LayoutTests/CollapsibleFlowLayoutTests.swift

@@ -8,10 +8,12 @@
 
 @testable import ElementX
 import SwiftUI
-import XCTest
+import Testing
 
-final class CollapsibleFlowLayoutTests: XCTestCase {
-    func testFlowLayoutWithExpandAndCollapse() {
+@Suite
+struct CollapsibleFlowLayoutTests {
+    @Test
+    func flowLayoutWithExpandAndCollapse() {
         let containerSize = CGSize(width: 250, height: 400)
         var flowLayout = CollapsibleReactionLayout(itemSpacing: 5, rowSpacing: 5, rowsBeforeCollapsible: 2)
         
@@ -25,7 +27,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
         var size = flowLayout.sizeThatFits(proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         // Collapsed target layout has 2 rows of 2 items, so just 1 spacing between items hence 205, 105
-        XCTAssertEqual(size, CGSize(width: 205, height: 105))
+        #expect(size == CGSize(width: 205, height: 105))
         flowLayout.placeSubviews(in: CGRect(origin: .zero, size: size), proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         // 4 items are hidden in the collapsed state (put in the centre with zero size)
@@ -39,7 +41,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
             CGRect(x: -10000, y: -10000, width: 0, height: 0),
             CGRect(x: -10000, y: -10000, width: 0, height: 0)
         ]
-        XCTAssertEqual(placedViews, targetPlacements)
+        #expect(placedViews == targetPlacements)
         
         flowLayout.collapsed = false
         placedViews = []
@@ -47,7 +49,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
         size = flowLayout.sizeThatFits(proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         // Expanded target layout has 4 rows and no more than 2 items per row
-        XCTAssertEqual(size, CGSize(width: 205, height: 215))
+        #expect(size == CGSize(width: 205, height: 215))
         
         flowLayout.placeSubviews(in: CGRect(origin: .zero, size: size), proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
@@ -61,10 +63,11 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
             CGRect(x: 0, y: 190, width: 100, height: 50),
             CGRect(x: 105.0, y: 190, width: 100, height: 50)
         ]
-        XCTAssertEqual(placedViews, targetPlacements)
+        #expect(placedViews == targetPlacements)
     }
     
-    func testFlowLayoutWithExpandButtonAndAddMoreIsHidden() {
+    @Test
+    func flowLayoutWithExpandButtonAndAddMoreIsHidden() {
         let containerSize = CGSize(width: 250, height: 400)
         let flowLayout = CollapsibleReactionLayout(itemSpacing: 5, rowSpacing: 5, rowsBeforeCollapsible: 2)
         
@@ -78,7 +81,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
         var a: () = ()
         let size = flowLayout.sizeThatFits(proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
-        XCTAssertEqual(size, CGSize(width: 205, height: 105))
+        #expect(size == CGSize(width: 205, height: 105))
         flowLayout.placeSubviews(in: CGRect(origin: .zero, size: size), proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         let targetPlacements: [CGRect] = [
@@ -90,10 +93,11 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
             // Expand/Collapse button is hidden
             CGRect(x: -10000, y: -10000, width: 0, height: 0)
         ]
-        XCTAssertEqual(placedViews, targetPlacements)
+        #expect(placedViews == targetPlacements)
     }
     
-    func testHeightIsCorrectGivenASmallerAddButton() {
+    @Test
+    func heightIsCorrectGivenASmallerAddButton() {
         let containerSize = CGSize(width: 250, height: 400)
         let flowLayout = CollapsibleReactionLayout(itemSpacing: 5, rowSpacing: 5, rowsBeforeCollapsible: 2)
         
@@ -110,7 +114,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
         var a: () = ()
         let size = flowLayout.sizeThatFits(proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
-        XCTAssertEqual(size, CGSize(width: 205, height: 105))
+        #expect(size == CGSize(width: 205, height: 105))
         flowLayout.placeSubviews(in: CGRect(origin: .zero, size: size), proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         let targetPlacements: [CGRect] = [
@@ -121,10 +125,11 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
             // Expand/Collapse button is hidden
             CGRect(x: -10000, y: -10000, width: 0, height: 0)
         ]
-        XCTAssertEqual(placedViews, targetPlacements)
+        #expect(placedViews == targetPlacements)
     }
     
-    func testFlowLayoutEmptyState() {
+    @Test
+    func flowLayoutEmptyState() {
         let containerSize = CGSize(width: 250, height: 400)
         let flowLayout = CollapsibleReactionLayout(itemSpacing: 5, rowSpacing: 5, rowsBeforeCollapsible: 2)
         
@@ -137,7 +142,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
         var a: () = ()
         let size = flowLayout.sizeThatFits(proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
-        XCTAssertEqual(size, CGSize(width: 0, height: 0))
+        #expect(size == CGSize(width: 0, height: 0))
         flowLayout.placeSubviews(in: CGRect(origin: .zero, size: size), proposal: ProposedViewSize(containerSize), subviews: subviewsMock, cache: &a)
         
         let targetPlacements: [CGRect] = [
@@ -145,7 +150,7 @@ final class CollapsibleFlowLayoutTests: XCTestCase {
             CGRect(x: -10000, y: -10000, width: 0, height: 0),
             CGRect(x: -10000, y: -10000, width: 0, height: 0)
         ]
-        XCTAssertEqual(placedViews, targetPlacements)
+        #expect(placedViews == targetPlacements)
     }
     
     func createReactionLayoutSubviews(with sizes: [CGSize],