QR login from device manager (#6818)

* Add link device button into the sessions overview screen

* Run Swift format

* Fix tests

* Fix a crash in tests

* Fix PR remark

RiotSwiftUI/Modules/UserSessions/UserSessionsOverview/View/UserSessionsOverview.swift

@@ -22,15 +22,25 @@ struct UserSessionsOverview: View {
     @ObservedObject var viewModel: UserSessionsOverviewViewModel.Context
     
     var body: some View {
-        ScrollView {
-            if hasSecurityRecommendations {
-                securityRecommendationsSection
-            }
-            
-            currentSessionsSection
-            
-            if !viewModel.viewState.otherSessionsViewData.isEmpty {
-                otherSessionsSection
+        GeometryReader { geometry in
+            VStack(alignment: .leading, spacing: 0) {
+                ScrollView {
+                    if hasSecurityRecommendations {
+                        securityRecommendationsSection
+                    }
+
+                    currentSessionsSection
+
+                    if !viewModel.viewState.otherSessionsViewData.isEmpty {
+                        otherSessionsSection
+                    }
+                }
+                .readableFrame()
+
+                if viewModel.viewState.linkDeviceButtonVisible {
+                    linkDeviceView
+                        .padding(.bottom, geometry.safeAreaInsets.bottom > 0 ? 20 : 36)
+                }
             }
         }
         .background(theme.colors.system.ignoresSafeArea())
@@ -158,6 +168,23 @@ struct UserSessionsOverview: View {
         }
         .accessibilityIdentifier("userSessionsOverviewOtherSection")
     }
+
+    /// The footer view containing link device button.
+    var linkDeviceView: some View {
+        VStack {
+            Button {
+                viewModel.send(viewAction: .linkDevice)
+            } label: {
+                Text(VectorL10n.userSessionsOverviewLinkDevice)
+            }
+            .buttonStyle(PrimaryActionButtonStyle(font: theme.fonts.bodySB))
+            .padding(.top, 28)
+            .padding(.bottom, 12)
+            .padding(.horizontal, 16)
+            .accessibilityIdentifier("linkDeviceButton")
+        }
+        .background(theme.colors.system.ignoresSafeArea())
+    }
 }
 
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