Пустой чат: glass-подложка и composer на iOS < 26, empty state анимируется с клавиатурой через UIKit

RosettaTests/ReplyPreviewTextTests.swift

@@ -74,6 +74,18 @@ final class ReplyPreviewTextTests: XCTestCase {
     private static func isGarbageText(_ text: String) -> Bool {
         let trimmed = text.trimmingCharacters(in: .whitespacesAndNewlines)
         if trimmed.isEmpty { return true }
+
+        // Detect encrypted payload: ivBase64:ctBase64 format
+        let parts = trimmed.components(separatedBy: ":")
+        if parts.count == 2 {
+            let base64Chars = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "+/="))
+            let bothBase64 = parts.allSatisfy { part in
+                part.count >= 16 && part.unicodeScalars.allSatisfy { base64Chars.contains($0) }
+            }
+            if bothBase64 { return true }
+        }
+        if trimmed.hasPrefix("CHNK:") { return true }
+
         let validCharacters = trimmed.unicodeScalars.filter { scalar in
             scalar.value != 0xFFFD &&
             scalar.value > 0x1F &&