test: add E2E tests for new session RPC features (mode, plan, workspace)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: SteveSandersonMS

nodejs/test/e2e/rpc.test.ts

@@ -94,4 +94,80 @@ describe("Session RPC", async () => {
         const after = await session.rpc.model.getCurrent();
         expect(after.modelId).toBe("gpt-4.1");
     });
+
+    it("should get and set session mode", async () => {
+        const session = await client.createSession();
+
+        // Get initial mode (default should be interactive)
+        const initial = await session.rpc.mode.get();
+        expect(initial.mode).toBe("interactive");
+
+        // Switch to plan mode
+        const planResult = await session.rpc.mode.set({ mode: "plan" });
+        expect(planResult.mode).toBe("plan");
+
+        // Verify mode persisted
+        const afterPlan = await session.rpc.mode.get();
+        expect(afterPlan.mode).toBe("plan");
+
+        // Switch back to interactive
+        const interactiveResult = await session.rpc.mode.set({ mode: "interactive" });
+        expect(interactiveResult.mode).toBe("interactive");
+    });
+
+    it("should read, update, and delete plan", async () => {
+        const session = await client.createSession();
+
+        // Initially plan should not exist
+        const initial = await session.rpc.plan.read();
+        expect(initial.exists).toBe(false);
+        expect(initial.content).toBeNull();
+
+        // Create/update plan
+        const planContent = "# Test Plan\n\n- Step 1\n- Step 2";
+        await session.rpc.plan.update({ content: planContent });
+
+        // Verify plan exists and has correct content
+        const afterUpdate = await session.rpc.plan.read();
+        expect(afterUpdate.exists).toBe(true);
+        expect(afterUpdate.content).toBe(planContent);
+
+        // Delete plan
+        await session.rpc.plan.delete();
+
+        // Verify plan is deleted
+        const afterDelete = await session.rpc.plan.read();
+        expect(afterDelete.exists).toBe(false);
+        expect(afterDelete.content).toBeNull();
+    });
+
+    it("should create, list, and read workspace files", async () => {
+        const session = await client.createSession();
+
+        // Initially no files
+        const initialFiles = await session.rpc.workspace.listFiles();
+        expect(initialFiles.files).toEqual([]);
+
+        // Create a file
+        const fileContent = "Hello, workspace!";
+        await session.rpc.workspace.createFile({ path: "test.txt", content: fileContent });
+
+        // List files
+        const afterCreate = await session.rpc.workspace.listFiles();
+        expect(afterCreate.files).toContain("test.txt");
+
+        // Read file
+        const readResult = await session.rpc.workspace.readFile({ path: "test.txt" });
+        expect(readResult.content).toBe(fileContent);
+
+        // Create nested file
+        await session.rpc.workspace.createFile({
+            path: "subdir/nested.txt",
+            content: "Nested content",
+        });
+
+        const afterNested = await session.rpc.workspace.listFiles();
+        expect(afterNested.files).toContain("test.txt");
+        expect(afterNested.files.some((f) => f.includes("nested.txt"))).toBe(true);
+    });
 });