Add screenshot generator

Library/Shared/ScreenshotLocalization.swift

@@ -0,0 +1,42 @@
+import Foundation
+import ObjectiveC
+
+private var screenshotLocalizationBundleKey: UInt8 = 0
+
+private final class ScreenshotBundle: Bundle, @unchecked Sendable {
+    override func localizedString(forKey key: String, value: String?, table tableName: String?) -> String {
+        if let bundle = objc_getAssociatedObject(self, &screenshotLocalizationBundleKey) as? Bundle {
+            return bundle.localizedString(forKey: key, value: value, table: tableName)
+        }
+        return super.localizedString(forKey: key, value: value, table: tableName)
+    }
+}
+
+public enum ScreenshotLocalization {
+    public static func applyIfNeeded() {
+        let environment = ProcessInfo.processInfo.environment
+        guard let language = environment["SCREENSHOT_LANGUAGE"]?
+            .trimmingCharacters(in: .whitespacesAndNewlines),
+            !language.isEmpty
+        else {
+            return
+        }
+        UserDefaults.standard.set([language], forKey: "AppleLanguages")
+        if let locale = environment["SCREENSHOT_LOCALE"]?
+            .trimmingCharacters(in: .whitespacesAndNewlines),
+            !locale.isEmpty
+        {
+            UserDefaults.standard.set(locale, forKey: "AppleLocale")
+        }
+        if let path = Bundle.main.path(forResource: language, ofType: "lproj"),
+           let localizedBundle = Bundle(path: path)
+        {
+            objc_setAssociatedObject(Bundle.main, &screenshotLocalizationBundleKey, localizedBundle, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
+            object_setClass(Bundle.main, ScreenshotBundle.self)
+        }
+    }
+}
+
+private let _screenshotLocalizationApplied: Void = {
+    ScreenshotLocalization.applyIfNeeded()
+}()