feat: add hierarchical session tree navigator

src/server/app.remoteProxy.test.ts

@@ -1,7 +1,7 @@
 import { Readable } from "node:stream";
 import { describe, expect, it, vi } from "vitest";
 import { RemoteMachineRequestError, type MachineClient } from "./machines/machineClient.js";
-import { PI_PACKAGE_MUTATION_PROXY_TIMEOUT_MS } from "../shared/federatedRoutes.js";
+import { PI_PACKAGE_MUTATION_PROXY_TIMEOUT_MS, SESSION_TREE_NAVIGATION_PROXY_TIMEOUT_MS } from "../shared/federatedRoutes.js";
 import { appTestContext, fakeRemoteClient, registerAppTestHooks } from "./app.testSupport.js";
 
 registerAppTestHooks();
@@ -64,6 +64,28 @@ describe("buildApp remote machine proxy routes", () => {
     expect(request).toHaveBeenNthCalledWith(2, "POST", "/api/pi-packages/install", installBody, { timeoutMs: PI_PACKAGE_MUTATION_PROXY_TIMEOUT_MS });
   });
 
+  it("forwards remote session tree navigation with the model-operation timeout", async () => {
+    const addResponse = await appTestContext.app.inject({ method: "POST", url: "/api/machines", payload: { name: "Remote", baseUrl: "https://remote.example.test/" } });
+    const remote = addResponse.json<{ id: string }>();
+    const request = vi.fn<MachineClient["request"]>((method, path, body) => Promise.resolve({
+      statusCode: 200,
+      headers: { "content-type": "application/json" },
+      body: Readable.from([JSON.stringify({ method, path, body })]),
+    }));
+    appTestContext.remoteClient = fakeRemoteClient({ request });
+    const navigationBody = { cwd: "/repo", targetId: "entry-1", expectedLeafId: "leaf-1", summary: { mode: "default" } };
+
+    const response = await appTestContext.app.inject({
+      method: "POST",
+      url: `/api/machines/${remote.id}/sessions/s1/tree/navigate`,
+      payload: navigationBody,
+    });
+
+    expect(response.statusCode).toBe(200);
+    expect(response.json()).toEqual({ method: "POST", path: "/api/sessions/s1/tree/navigate", body: navigationBody });
+    expect(request).toHaveBeenCalledWith("POST", "/api/sessions/s1/tree/navigate", navigationBody, { timeoutMs: SESSION_TREE_NAVIGATION_PROXY_TIMEOUT_MS });
+  });
+
   it("proxies remote workspace effective upload config through the existing federated workspace route", async () => {
     const addResponse = await appTestContext.app.inject({ method: "POST", url: "/api/machines", payload: { name: "Remote", baseUrl: "https://remote.example.test/" } });
     const remote = addResponse.json<{ id: string }>();