fix(#338): Gate mock data behind NODE_ENV check

- Create ComingSoon component for production placeholders
- Federation connections page shows Coming Soon in production
- Workspaces settings page shows Coming Soon in production
- Teams page shows Coming Soon in production
- Add comprehensive tests for environment-based rendering

Refs #338

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/src/app/(authenticated)/settings/workspaces/page.test.tsx

@@ -0,0 +1,60 @@
+/**
+ * Workspaces Page Tests
+ * Tests for page structure and component integration
+ */
+
+import { describe, it, expect, vi } from "vitest";
+import { render, screen } from "@testing-library/react";
+
+// Mock next/link
+vi.mock("next/link", () => ({
+  default: ({ children, href }: { children: React.ReactNode; href: string }): React.JSX.Element => (
+    <a href={href}>{children}</a>
+  ),
+}));
+
+// Mock the WorkspaceCard component
+vi.mock("@/components/workspace/WorkspaceCard", () => ({
+  WorkspaceCard: (): React.JSX.Element => <div data-testid="workspace-card">WorkspaceCard</div>,
+}));
+
+describe("WorkspacesPage", (): void => {
+  // Note: NODE_ENV is "test" during test runs, which triggers the Coming Soon view
+  // This tests the production-like behavior where mock data is hidden
+
+  it("should render the Coming Soon view in non-development environments", async (): Promise<void> => {
+    const { default: WorkspacesPage } = await import("./page");
+    render(<WorkspacesPage />);
+
+    // In test mode (non-development), should show Coming Soon
+    expect(screen.getByText("Coming Soon")).toBeInTheDocument();
+    expect(screen.getByText("Workspace Management")).toBeInTheDocument();
+  });
+
+  it("should display appropriate description for workspace feature", async (): Promise<void> => {
+    const { default: WorkspacesPage } = await import("./page");
+    render(<WorkspacesPage />);
+
+    expect(
+      screen.getByText(/create and manage workspaces to organize your projects/i)
+    ).toBeInTheDocument();
+  });
+
+  it("should not render mock workspace data in Coming Soon view", async (): Promise<void> => {
+    const { default: WorkspacesPage } = await import("./page");
+    render(<WorkspacesPage />);
+
+    // Should not show workspace cards or create form in non-development mode
+    expect(screen.queryByTestId("workspace-card")).not.toBeInTheDocument();
+    expect(screen.queryByText("Create New Workspace")).not.toBeInTheDocument();
+  });
+
+  it("should include link back to settings", async (): Promise<void> => {
+    const { default: WorkspacesPage } = await import("./page");
+    render(<WorkspacesPage />);
+
+    const link = screen.getByRole("link", { name: /back to settings/i });
+    expect(link).toBeInTheDocument();
+    expect(link).toHaveAttribute("href", "/settings");
+  });
+});