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/components/ui/ComingSoon.test.tsx

@@ -0,0 +1,51 @@
+/**
+ * ComingSoon Component Tests
+ * Tests for the production placeholder component
+ */
+
+import { describe, it, expect } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { ComingSoon } from "./ComingSoon";
+
+describe("ComingSoon", (): void => {
+  it("should render with default props", (): void => {
+    render(<ComingSoon feature="Test Feature" />);
+
+    expect(screen.getByText("Coming Soon")).toBeInTheDocument();
+    expect(screen.getByText("Test Feature")).toBeInTheDocument();
+    expect(screen.getByText(/This feature is currently under development/i)).toBeInTheDocument();
+  });
+
+  it("should render custom description", (): void => {
+    render(<ComingSoon feature="Custom Feature" description="Custom description text" />);
+
+    expect(screen.getByText("Custom Feature")).toBeInTheDocument();
+    expect(screen.getByText("Custom description text")).toBeInTheDocument();
+  });
+
+  it("should render children when provided", (): void => {
+    render(
+      <ComingSoon feature="Feature">
+        <div data-testid="child-content">Child content</div>
+      </ComingSoon>
+    );
+
+    expect(screen.getByTestId("child-content")).toBeInTheDocument();
+    expect(screen.getByText("Child content")).toBeInTheDocument();
+  });
+
+  it("should apply custom className", (): void => {
+    render(<ComingSoon feature="Test" className="custom-class" />);
+
+    const container = screen.getByRole("main");
+    expect(container).toHaveClass("custom-class");
+  });
+
+  it("should render construction icon by default", (): void => {
+    render(<ComingSoon feature="Test" />);
+
+    // The icon should be present (as an SVG)
+    const svg = document.querySelector("svg");
+    expect(svg).toBeInTheDocument();
+  });
+});

apps/web/src/components/ui/ComingSoon.tsx

@@ -0,0 +1,72 @@
+/**
+ * ComingSoon Component
+ * Displays a placeholder for features not yet available in production.
+ * Used to prevent mock data from being shown to production users.
+ */
+
+import type { ReactElement, ReactNode } from "react";
+
+export interface ComingSoonProps {
+  /** The name of the feature being developed */
+  feature: string;
+  /** Optional custom description */
+  description?: string;
+  /** Optional children to render below the message */
+  children?: ReactNode;
+  /** Optional className for the container */
+  className?: string;
+}
+
+/**
+ * ComingSoon displays a friendly placeholder for incomplete features.
+ * Use this in production when a feature is under development to avoid
+ * showing mock or placeholder data to users.
+ */
+export function ComingSoon({
+  feature,
+  description,
+  children,
+  className = "",
+}: ComingSoonProps): ReactElement {
+  const defaultDescription =
+    "This feature is currently under development and will be available soon.";
+
+  return (
+    <main className={`container mx-auto px-4 py-8 max-w-3xl ${className}`} role="main">
+      <div className="flex flex-col items-center justify-center min-h-[400px] bg-gray-50 rounded-lg border border-gray-200 p-8 text-center">
+        {/* Construction Icon */}
+        <svg
+          className="w-16 h-16 text-blue-400 mb-6"
+          fill="none"
+          stroke="currentColor"
+          viewBox="0 0 24 24"
+          xmlns="http://www.w3.org/2000/svg"
+          aria-hidden="true"
+        >
+          <path
+            strokeLinecap="round"
+            strokeLinejoin="round"
+            strokeWidth={1.5}
+            d="M19.428 15.428a2 2 0 00-1.022-.547l-2.387-.477a6 6 0 00-3.86.517l-.318.158a6 6 0 01-3.86.517L6.05 15.21a2 2 0 00-1.806.547M8 4h8l-1 1v5.172a2 2 0 00.586 1.414l5 5c1.26 1.26.367 3.414-1.415 3.414H4.828c-1.782 0-2.674-2.154-1.414-3.414l5-5A2 2 0 009 10.172V5L8 4z"
+          />
+        </svg>
+
+        {/* Coming Soon Badge */}
+        <span className="inline-block px-4 py-1.5 bg-blue-100 text-blue-700 text-sm font-medium rounded-full mb-4">
+          Coming Soon
+        </span>
+
+        {/* Feature Name */}
+        <h1 className="text-2xl font-bold text-gray-900 mb-3">{feature}</h1>
+
+        {/* Description */}
+        <p className="text-gray-600 max-w-md mb-6">{description ?? defaultDescription}</p>
+
+        {/* Optional Children */}
+        {children && <div className="mt-4">{children}</div>}
+      </div>
+    </main>
+  );
+}
+
+export default ComingSoon;