fix(chat): avoid overwriting user messages on unlock

src/stores/chat/chat-unlock-helpers.ts

@@ -16,7 +16,7 @@ export function applySingleUnlockOutput(
   if (!output.response.unlocked) return [...messages];
 
   return messages.map((message) => {
-    if (message.id !== output.messageId) return message;
+    if (!shouldApplySingleUnlock(message, output.messageId)) return message;
 
     const nextContent =
       output.response.content.length > 0
@@ -38,6 +38,17 @@ export function applySingleUnlockOutput(
   });
 }
 
+function shouldApplySingleUnlock(message: UiMessage, messageId: string): boolean {
+  if (message.id !== messageId) return false;
+  if (!message.isFromAI) return false;
+  if (message.locked !== true) return false;
+  return (
+    message.imagePaywalled === true ||
+    message.lockReason === "private_message" ||
+    message.lockReason === "voice_message"
+  );
+}
+
 export function shouldAutoUnlockHistory(messages: readonly UiMessage[]): boolean {
   return countLockedHistoryMessages(messages) === 1;
 }