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");
+  });
+});

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

@@ -4,10 +4,14 @@ import type { ReactElement } from "react";
 
 import { useState } from "react";
 import { WorkspaceCard } from "@/components/workspace/WorkspaceCard";
+import { ComingSoon } from "@/components/ui/ComingSoon";
 import { WorkspaceMemberRole } from "@mosaic/shared";
 import Link from "next/link";
 
-// Mock data - TODO: Replace with real API calls
+// Check if we're in development mode
+const isDevelopment = process.env.NODE_ENV === "development";
+
+// Mock data - TODO: Replace with real API calls (development only)
 const mockWorkspaces = [
   {
     id: "ws-1",
@@ -32,7 +36,11 @@ const mockMemberships = [
   { workspaceId: "ws-2", role: WorkspaceMemberRole.MEMBER, memberCount: 5 },
 ];
 
-export default function WorkspacesPage(): ReactElement {
+/**
+ * Workspaces Page Content - Development Only
+ * Shows mock workspace data for development purposes
+ */
+function WorkspacesPageContent(): ReactElement {
   const [isCreating, setIsCreating] = useState(false);
   const [newWorkspaceName, setNewWorkspaceName] = useState("");
 
@@ -140,3 +148,26 @@ export default function WorkspacesPage(): ReactElement {
     </main>
   );
 }
+
+/**
+ * Workspaces Page Entry Point
+ * Shows development content or Coming Soon based on environment
+ */
+export default function WorkspacesPage(): ReactElement {
+  // In production, show Coming Soon placeholder
+  if (!isDevelopment) {
+    return (
+      <ComingSoon
+        feature="Workspace Management"
+        description="Create and manage workspaces to organize your projects and collaborate with your team. This feature is currently under development."
+      >
+        <Link href="/settings" className="text-sm text-blue-600 hover:text-blue-700">
+          Back to Settings
+        </Link>
+      </ComingSoon>
+    );
+  }
+
+  // In development, show the full page with mock data
+  return <WorkspacesPageContent />;
+}