fix(app): stop completed turns from appearing stuck

Turn activity was inferred from a user-message row flag, so a stale duplicate row could keep the working footer active after the turn ended. Track submission lifecycle separately and route every send path through the shared submission flow.

packages/server/src/server/agent/providers/mock-load-test-agent.test.ts

@@ -49,6 +49,25 @@ describe("MockLoadTestAgentClient", () => {
     });
   });
 
+  test("rejects the configured number of prompts before starting a retry", async () => {
+    const client = new MockLoadTestAgentClient();
+    const session = await client.createSession({
+      provider: "mock",
+      cwd: process.cwd(),
+      model: "ten-second-stream",
+      featureValues: { mockPromptRejections: 1 },
+    });
+
+    await expect(session.startTurn("Reject this prompt.")).rejects.toThrow(
+      "Requested mock prompt rejection",
+    );
+
+    await expect(session.startTurn("Accept this retry.")).resolves.toEqual({
+      turnId: expect.any(String),
+    });
+    await session.interrupt();
+  });
+
   test("returns schema-shaped JSON for structured branch-name generation", async () => {
     vi.useFakeTimers();
     const client = new MockLoadTestAgentClient();

packages/server/src/server/agent/providers/mock-load-test-agent.ts

@@ -583,6 +583,7 @@ export class MockLoadTestAgentSession implements AgentSession {
   private modeId: string | null;
   private modelId: string | null;
   private readonly rewindError: string | null;
+  private remainingPromptRejections: number;
 
   constructor(options: { config: AgentSessionConfig; sessionId: string; logger?: Logger }) {
     this.id = options.sessionId;
@@ -593,6 +594,13 @@ export class MockLoadTestAgentSession implements AgentSession {
       typeof options.config.featureValues?.mockRewindError === "string"
         ? options.config.featureValues.mockRewindError
         : null;
+    const requestedPromptRejections = options.config.featureValues?.mockPromptRejections;
+    this.remainingPromptRejections =
+      typeof requestedPromptRejections === "number" &&
+      Number.isSafeInteger(requestedPromptRejections) &&
+      requestedPromptRejections > 0
+        ? requestedPromptRejections
+        : 0;
   }
 
   async run(prompt: AgentPromptInput, options?: AgentRunOptions): Promise<AgentRunResult> {
@@ -611,6 +619,10 @@ export class MockLoadTestAgentSession implements AgentSession {
     if (this.activeTurn) {
       throw new Error("Mock load-test provider already has an active turn");
     }
+    if (this.remainingPromptRejections > 0) {
+      this.remainingPromptRejections -= 1;
+      throw new Error("Requested mock prompt rejection");
+    }
 
     const profile = resolveModelProfile(this.modelId);
     const turnId = randomUUID();