fix(chat): sync paid voice audio unlock flow

src/stores/chat/__tests__/chat-machine.helpers.test.ts

@@ -14,7 +14,6 @@ function makeResponse(
 ): ChatSendResponse {
   return ChatSendResponse.from({
     reply: "AI reply",
-    audioUrl: "",
     messageId: "msg-1",
     isGuest: false,
     timestamp: 1782356425363,
@@ -62,7 +61,6 @@ describe("sendResponseToUiMessage", () => {
   it("maps locked voice messages without treating them as private text", () => {
     const message = sendResponseToUiMessage(
       makeResponse({
-        audioUrl: "",
         lockDetail: {
           locked: true,
           reason: "voice_message",
@@ -78,6 +76,34 @@ describe("sendResponseToUiMessage", () => {
     expect(message.privateMessageHint).toBeUndefined();
   });
 
+  it("does not expose an audio URL from a locked send response", () => {
+    const message = sendResponseToUiMessage(
+      makeResponse({
+        audioUrl: "https://example.com/locked-voice.mp3",
+        lockDetail: {
+          locked: true,
+          reason: "voice_message",
+        },
+      }),
+    );
+
+    expect(message.audioUrl).toBeUndefined();
+    expect(message.locked).toBe(true);
+  });
+
+  it("maps an audio URL from an unlocked send response", () => {
+    const message = sendResponseToUiMessage(
+      makeResponse({
+        audioUrl: "https://example.com/unlocked-voice.mp3",
+      }),
+    );
+
+    expect(message.audioUrl).toBe(
+      "https://example.com/unlocked-voice.mp3",
+    );
+    expect(message.locked).toBe(false);
+  });
+
   it("maps locked private text messages as private messages", () => {
     const message = sendResponseToUiMessage(
       makeResponse({
@@ -227,7 +253,7 @@ describe("localMessagesToUi", () => {
         type: "voice",
         content: "hidden voice transcript",
         createdAt: "2026-06-25T12:00:00.000Z",
-        audioUrl: null,
+        audioUrl: "https://example.com/locked-history-voice.mp3",
         image: { type: null, url: null },
         lockDetail: {
           locked: true,

src/stores/chat/__tests__/chat-machine.transitions.test.ts

@@ -57,10 +57,6 @@ function makeUnlockPrivateResponse(
     creditsCharged: 10,
     requiredCredits: 10,
     shortfallCredits: 0,
-    lockDetail: {
-      locked: false,
-      reason: null,
-    },
     ...overrides,
   });
 }
@@ -822,10 +818,6 @@ describe("chatMachine transitions", () => {
             creditsCharged: 0,
             requiredCredits: 10,
             shortfallCredits: 7,
-            lockDetail: {
-              locked: true,
-              reason: "voice_message",
-            },
           }),
         },
       }),

src/stores/chat/__tests__/chat-promotion.test.ts

@@ -57,10 +57,6 @@ describe("chat promotion", () => {
           type: "promotion",
           url: "https://example.com/unlocked.jpg",
         },
-        lockDetail: {
-          locked: false,
-          reason: null,
-        },
       }),
     });