fix(chat): preserve locked message content on unlock

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

@@ -480,7 +480,7 @@ describe("chatMachine transitions", () => {
         historyMessages: [
           {
             id: "msg-private-locked",
-            content: "",
+            content: "Original private message content.",
             isFromAI: true,
             date: "2026-06-29",
             locked: true,
@@ -492,7 +492,7 @@ describe("chatMachine transitions", () => {
         unlockMessageOutput: {
           messageId: "msg-private-locked",
           response: makeUnlockPrivateResponse({
-            content: "This is the unlocked private message.",
+            content: "This response content must be ignored.",
           }),
         },
       }),
@@ -518,7 +518,7 @@ describe("chatMachine transitions", () => {
     expect(actor.getSnapshot().context.messages).toMatchObject([
       {
         id: "msg-private-locked",
-        content: "This is the unlocked private message.",
+        content: "Original private message content.",
         locked: false,
         lockReason: null,
         lockedPrivate: false,
@@ -541,7 +541,7 @@ describe("chatMachine transitions", () => {
           },
           {
             id: "msg-shared-id",
-            content: "",
+            content: "Original AI private message",
             isFromAI: true,
             date: "2026-06-29",
             locked: true,
@@ -553,7 +553,7 @@ describe("chatMachine transitions", () => {
         unlockMessageOutput: {
           messageId: "msg-shared-id",
           response: makeUnlockPrivateResponse({
-            content: "This is the unlocked private message.",
+            content: "This response content must be ignored.",
           }),
         },
       }),
@@ -582,7 +582,7 @@ describe("chatMachine transitions", () => {
       },
       {
         id: "msg-shared-id",
-        content: "This is the unlocked private message.",
+        content: "Original AI private message",
         isFromAI: true,
         locked: false,
         lockReason: null,
@@ -594,6 +594,112 @@ describe("chatMachine transitions", () => {
     actor.stop();
   });
 
+  it("keeps image message text empty after a single image unlock succeeds", async () => {
+    const actor = createActor(
+      createTestChatMachine({
+        historyMessages: [
+          {
+            id: "msg-image-locked",
+            content: "",
+            isFromAI: true,
+            date: "2026-06-29",
+            imageUrl: "https://example.com/locked.jpg",
+            imagePaywalled: true,
+            locked: true,
+            lockReason: "image",
+          },
+        ],
+        unlockMessageOutput: {
+          messageId: "msg-image-locked",
+          response: makeUnlockPrivateResponse({
+            content: "This text should not render below the image.",
+          }),
+        },
+      }),
+    ).start();
+
+    actor.send({ type: "ChatUserLogin", token: "token" });
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+
+    actor.send({
+      type: "ChatUnlockMessageRequested",
+      messageId: "msg-image-locked",
+      kind: "image",
+    });
+
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+
+    expect(actor.getSnapshot().context.messages).toMatchObject([
+      {
+        id: "msg-image-locked",
+        content: "",
+        imageUrl: "https://example.com/locked.jpg",
+        imagePaywalled: false,
+        locked: false,
+        lockReason: null,
+      },
+    ]);
+
+    actor.stop();
+  });
+
+  it("keeps voice message content unchanged after unlock succeeds", async () => {
+    const actor = createActor(
+      createTestChatMachine({
+        historyMessages: [
+          {
+            id: "msg-voice-locked",
+            content: "Original voice transcript.",
+            isFromAI: true,
+            date: "2026-06-29",
+            audioUrl: "https://example.com/voice.mp3",
+            locked: true,
+            lockReason: "voice_message",
+            privateMessageHint: "A voice message is waiting.",
+          },
+        ],
+        unlockMessageOutput: {
+          messageId: "msg-voice-locked",
+          response: makeUnlockPrivateResponse({
+            content: "This response content must be ignored.",
+          }),
+        },
+      }),
+    ).start();
+
+    actor.send({ type: "ChatUserLogin", token: "token" });
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+
+    actor.send({
+      type: "ChatUnlockMessageRequested",
+      messageId: "msg-voice-locked",
+      kind: "voice",
+    });
+
+    await waitFor(actor, (snapshot) =>
+      snapshot.matches({ userSession: "ready" }),
+    );
+
+    expect(actor.getSnapshot().context.messages).toMatchObject([
+      {
+        id: "msg-voice-locked",
+        content: "Original voice transcript.",
+        audioUrl: "https://example.com/voice.mp3",
+        locked: false,
+        lockReason: null,
+        privateMessageHint: null,
+      },
+    ]);
+
+    actor.stop();
+  });
+
   it("requests payment when single message unlock lacks credits", async () => {
     const actor = createActor(
       createTestChatMachine({