feat(FN-3329): refine dashboard TUI system panel and setup wizard UX

- Expand dashboard TUI state/controller wiring for system panel interactions and mouse toggle behavior
- Update dashboard TUI app rendering and tests to cover the new panel controls
- Improve SetupWizardModal layout and interaction behavior with matching CSS and test updates
- Restore docs/research.md wording and add a changeset for the published CLI package

Fusion-Task-Id: FN-3329

packages/cli/src/commands/dashboard-tui/__tests__/app.test.tsx

@@ -3,6 +3,7 @@ import { describe, it, expect, vi, afterEach } from "vitest";
 import { render } from "ink-testing-library";
 import { DashboardApp } from "../app.js";
 import { DashboardTUI } from "../controller.js";
+import { createInitialState } from "../state.js";
 import type { ProjectItem, TaskItem, AgentItem, AgentDetailItem, ModelItem, SettingsValues, TaskDetailData } from "../state.js";
 
 function newController(): DashboardTUI {
@@ -233,6 +234,23 @@ describe("DashboardApp smoke", () => {
   });
 });
 
+describe("Default active section", () => {
+  it("createInitialState defaults to system panel", () => {
+    const state = createInitialState();
+    expect(state.activeSection).toBe("system");
+  });
+
+  it("DashboardTUI controller defaults to system panel", () => {
+    const controller = newController();
+    expect(controller.getSnapshot().activeSection).toBe("system");
+  });
+
+  it("createInitialState defaults to mouseEnabled = true", () => {
+    const state = createInitialState();
+    expect(state.mouseEnabled).toBe(true);
+  });
+});
+
 describe("DashboardTUI snapshot stability", () => {
   it("returns the same snapshot reference across reads when state has not changed", () => {
     const controller = newController();