Add Security and Application Safeguards

Task

Finish the application-level safeguards that should exist before deployment.

Review the application security headers in proxy.ts and ensure they are applied consistently.

Keep server-only modules server-only and verify that secrets are never imported into client components.

Add same-origin protection to state-changing browser requests where the application’s architecture requires it.

Review error responses so internal stack traces, storage credentials, database details, and password data are not returned to clients.

Audit dependency and build warnings before the final module.

Test

Inspect representative responses and confirm the expected security headers are present.

Trigger validation, authentication, ownership, and storage errors and confirm the browser receives safe error messages.

Run:

npm run lint
npm run typecheck

Fix issues introduced by the hardening work.

Checkpoint

Readly has a production-minded security baseline and a clean lint/typecheck result.

Module Complete

The application is now responsive and hardened around its most important trust boundaries. Module 12 finishes the project with end-to-end testing and deployment.