feat(integrations): add mock integration (#3505)

apps/nextjs/src/env.ts

@@ -0,0 +1,9 @@
+import { createEnv } from "@homarr/env";
+import { createBooleanSchema } from "@homarr/env/schemas";
+
+export const env = createEnv({
+  server: {
+    UNSAFE_ENABLE_MOCK_INTEGRATION: createBooleanSchema(false),
+  },
+  experimental__runtimeEnv: process.env,
+});