Telegram-style date pills в чат-листе — sticky headers с push-переходом между секциями

Rosetta/Features/Chats/ChatList/ChatRowView.swift

@@ -154,7 +154,13 @@ private extension ChatRowView {
         if isTyping && !dialog.isSavedMessages {
             return "typing..."
         }
-        if dialog.lastMessage.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+        let raw = dialog.lastMessage.trimmingCharacters(in: .whitespacesAndNewlines)
+        if raw.isEmpty {
+            return "No messages yet"
+        }
+        // Safety net: never show encrypted ciphertext (ivBase64:ctBase64) to user.
+        // This catches stale data persisted before isGarbageText was improved.
+        if Self.looksLikeCiphertext(raw) {
             return "No messages yet"
         }
         if let cached = Self.messageTextCache[dialog.lastMessage] {
@@ -170,6 +176,27 @@ private extension ChatRowView {
         Self.messageTextCache[dialog.lastMessage] = result
         return result
     }
+
+    /// Detects encrypted payload formats that should never be shown in UI.
+    private static func looksLikeCiphertext(_ text: String) -> Bool {
+        // CHNK: chunked format
+        if text.hasPrefix("CHNK:") { return true }
+        // ivBase64:ctBase64 or hex-encoded XChaCha20 ciphertext
+        let parts = text.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 }
+        }
+        // Pure hex string (≥40 chars, only hex digits) — XChaCha20 wire format
+        if text.count >= 40 {
+            let hexChars = CharacterSet(charactersIn: "0123456789abcdefABCDEF")
+            if text.unicodeScalars.allSatisfy({ hexChars.contains($0) }) { return true }
+        }
+        return false
+    }
 }
 
 // MARK: - Trailing Column