Add screenshot generator

SFTUITests/SnapshotHelper.swift

@@ -0,0 +1,58 @@
+import Foundation
+import XCTest
+
+private var screenshotsDir: URL!
+
+private func resolveScreenshotsDir() -> URL {
+    let env = ProcessInfo.processInfo.environment
+    if let override = env["SCREENSHOTS_DIR"], !override.isEmpty {
+        return URL(fileURLWithPath: override, isDirectory: true)
+    }
+    if let override = env["SNAPSHOT_SCREENSHOTS_PATH"], !override.isEmpty {
+        return URL(fileURLWithPath: override, isDirectory: true)
+    }
+    if let simulatorHostHome = env["SIMULATOR_HOST_HOME"] {
+        return URL(fileURLWithPath: simulatorHostHome)
+            .appendingPathComponent("Library/Caches/tools.fastlane/screenshots")
+    }
+    return URL(fileURLWithPath: NSHomeDirectory())
+        .appendingPathComponent("Library/Caches/tools.fastlane/screenshots")
+}
+
+@MainActor
+func setupSnapshot(_ app: XCUIApplication, waitForAnimations _: Bool = true) {
+    app.launchArguments += ["-FASTLANE_SNAPSHOT", "YES", "-ui_testing"]
+    screenshotsDir = resolveScreenshotsDir()
+    try! FileManager.default.createDirectory(at: screenshotsDir, withIntermediateDirectories: true)
+}
+
+@MainActor
+func snapshot(_ name: String, waitForLoadingIndicator: Bool = true) {
+    snapshot(name, timeWaitingForIdle: waitForLoadingIndicator ? 1 : 0)
+}
+
+@MainActor
+func snapshot(_ name: String, timeWaitingForIdle timeout: TimeInterval) {
+    if timeout > 0 {
+        sleep(UInt32(timeout))
+    }
+    let simulator = ProcessInfo.processInfo.environment["SIMULATOR_DEVICE_NAME"] ?? "AppleTV"
+    let screenshot = XCUIScreen.main.screenshot()
+    let path = screenshotsDir.appendingPathComponent("\(simulator)-\(name).png")
+    try! screenshot.pngRepresentation.write(to: path)
+}
+
+func loadScreenshotLanguage() -> (language: String?, locale: String?) {
+    let dir = resolveScreenshotsDir()
+    let language = readScreenshotText(dir.appendingPathComponent("language.txt"))
+    let locale = readScreenshotText(dir.appendingPathComponent("locale.txt"))
+    return (language, locale)
+}
+
+private func readScreenshotText(_ url: URL) -> String? {
+    guard let text = try? String(contentsOf: url, encoding: .utf8) else {
+        return nil
+    }
+    let trimmed = text.trimmingCharacters(in: .whitespacesAndNewlines)
+    return trimmed.isEmpty ? nil : trimmed
+}