docs: prepare final release submission documents

[kckagancan]

Summary

This PR adds the final release submission documentation and environment example cleanup.

It updates the root setup instructions so evaluators can clearly run, configure, seed, and release the web/backend/mobile applications. It also adds/updates env example files for backend, web, and Android release configuration.

Changes

• Updated root README.md with:

  • live deployment section
  • local Docker setup
  • backend setup
  • web setup
  • Android/mobile setup
  • production setup notes
  • data seeding instructions
  • default demo credentials
  • Android emulator network configuration
  • final release checklist

• Updated env examples:

  • backend/.env.example
  • web/.env.example
  • android/.env.example
  • android/keystore.properties.example

• Documented Android release configuration values and APK attachment requirement.

Notes

This is a docs/config-example only PR.

No application code, migrations, Docker config, Gradle config, package files, or lock files were changed.

Verification

• Checked README coverage against the final software release submission checklist.
• Confirmed documented env values match the current backend, web, and Android configuration expectations.

Closes #602

[erinc00]

Thanks for your effort, LGTM, approved and merging