fix(runner): bind provider model before terminal

packages/paperclip-runner/src/drivers/acpx/codex-runtime-adapter.test.ts

@@ -101,9 +101,9 @@ describe("Codex ACPX runtime adapter", () => {
     });
   });
 
-  it.each([["claude" as const, "claude-sonnet-5"]])(
+  it.each([["claude" as const, "claude-sonnet-5", "sonnet"]])(
     "opens the qualified %s session through the verified lease",
-    async (agent, model) => {
+    async (agent, model, providerModel) => {
       const runtime = fakeRuntime();
       const command = fakeCommand();
       const options = openOptions(command);
@@ -132,7 +132,7 @@ describe("Codex ACPX runtime adapter", () => {
       expect(runtime.ensureSession).toHaveBeenCalledWith(
         expect.objectContaining({
           agent,
-          sessionOptions: expect.objectContaining({ model }),
+          sessionOptions: expect.objectContaining({ model: providerModel }),
         }),
       );
     },

packages/paperclip-runner/src/drivers/acpx/codex-runtime-adapter.ts

@@ -296,7 +296,11 @@ export async function openQualifiedAcpxRuntime(
         mode: "persistent",
         cwd: options.cwd,
         sessionOptions: {
-          model: options.profile.qualificationModel,
+          // ACP session construction receives the provider-native selector.
+          // The caller-facing canonical model was already pinned when the
+          // qualified profile was resolved and is restored at the status
+          // boundary after the provider reports this selector.
+          model: options.profile.reportedModelId,
           ...(options.systemInstructions
             ? { systemPrompt: { append: options.systemInstructions } }
             : {}),

packages/paperclip-runner/src/drivers/acpx/runtime-host.test.ts

@@ -419,7 +419,7 @@ describe("ACPX runtime host", () => {
     const fixture = await hostFixture();
     let selected = false;
     const setModel = vi.fn(async (model: string) => {
-      expect(model).toBe("claude-sonnet-5");
+      expect(model).toBe("sonnet");
       selected = true;
     });
     const runtime = runtimePort({

packages/paperclip-runner/src/live/runnerd-codex-transport.ts

@@ -1532,6 +1532,7 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
   #providerIdentity: Record<string, unknown> | null = null;
   #turnId = "";
   #turnStartResponsePending = false;
+  #turnStartResponseEpoch = 0;
   #durableTurnId = "";
   #authorizedTools: Record<string, unknown> | null = null;
   #closed = false;
@@ -2766,7 +2767,9 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
       .join("\n");
     const pendingTurnId = `turn_lab_${randomUUID().replaceAll("-", "")}`;
     this.#turnId = pendingTurnId;
+    const responseEpoch = ++this.#turnStartResponseEpoch;
     this.#turnStartResponsePending = true;
+    let responseReady = false;
     try {
       await this.#command("turn.start", { text: message });
       // Command completion only means runnerd accepted the command. Codex assigns
@@ -2783,9 +2786,24 @@ class DurablePrpCodexTransport implements CodexAppServerTransport {
       }
       if (this.#turnId === pendingTurnId)
         throw new Error("runnerd did not report the provider turn identity");
+      responseReady = true;
       return { turn: { id: this.#turnId, status: "inProgress" } };
     } finally {
-      this.#turnStartResponsePending = false;
+      if (!responseReady) {
+        if (this.#turnStartResponseEpoch === responseEpoch)
+          this.#turnStartResponsePending = false;
+      } else {
+        // Resolving this async method schedules the strict driver's response
+        // continuation as a microtask. Keep terminal frames held until the
+        // following task so the driver can bind and emit turn.accepted first.
+        // The epoch prevents a late release from clearing a newer turn fence.
+        const release = setTimeout(() => {
+          if (this.#turnStartResponseEpoch !== responseEpoch) return;
+          this.#turnStartResponsePending = false;
+          if (!this.#closed) this.#pumpEventsSafely();
+        }, 0);
+        release.unref();
+      }
     }
   }