crypto: Add configuration flag to enable invisible crypto (#3247)

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/DeveloperOptionsScreenModels.swift

@@ -47,6 +47,7 @@ protocol DeveloperOptionsProtocol: AnyObject {
     var elementCallBaseURLOverride: URL? { get set }
     var fuzzyRoomListSearchEnabled: Bool { get set }
     var pinningEnabled: Bool { get set }
+    var invisibleCryptoEnabled: Bool { get set }
 }
 
 extension AppSettings: DeveloperOptionsProtocol { }

ElementX/Sources/Screens/Settings/DeveloperOptionsScreen/View/DeveloperOptionsScreen.swift

@@ -52,6 +52,17 @@ struct DeveloperOptionsScreen: View {
                 }
             }
             
+            Section {
+                Toggle(isOn: $context.invisibleCryptoEnabled) {
+                    Text("Enabled Invisible Crypto")
+                    Text("Requires app reboot")
+                }
+            } header: {
+                Text("Trust and Decoration")
+            } footer: {
+                Text("This setting controls how end-to-end encryption (E2EE) keys are shared. Enabling it will prevent the inclusion of devices that have not been explicitly verified by their owners.")
+            }
+
             Section {
                 TextField(context.viewState.elementCallBaseURL.absoluteString, text: $elementCallURLOverrideString)
                     .autocorrectionDisabled(true)