refactor(agent): remove legacy image mode prompt injection

webui/src/tests/nanobot-client.test.ts

@@ -528,33 +528,6 @@ describe("NanobotClient", () => {
     });
   });
 
-  it("includes image generation options in outbound messages", () => {
-    const client = new NanobotClient({
-      url: "ws://test",
-      reconnect: false,
-      socketFactory: (url) => new FakeSocket(url) as unknown as WebSocket,
-    });
-    client.connect();
-    lastSocket().fakeOpen();
-
-    client.sendMessage(
-      "chat-img",
-      "draw a banner",
-      undefined,
-      { imageGeneration: { enabled: true, aspect_ratio: "16:9" } },
-    );
-
-    expect(lastSocket().sent).toContain(
-      JSON.stringify({
-        type: "message",
-        chat_id: "chat-img",
-        content: "draw a banner",
-        image_generation: { enabled: true, aspect_ratio: "16:9" },
-        webui: true,
-      }),
-    );
-  });
-
   it("includes CLI app attachments in outbound messages", () => {
     const client = new NanobotClient({
       url: "ws://test",