Lazy load ERB for usr apps

[bstepanovski]

What does this PR do, and what is the related issue, if applicable?

Usr batch connect apps were rendering form.yml.erb when the dashboard loaded. This could run app code before the user actually opened the app.

This change skips that eager rendering for usr apps. Titles and other nav info use the manifest/router defaults until the form is opened. System apps are unchanged.

Fixes #5797

Testing

• Tests included
• If a maintainers' assistance is needed for tests, add label test help
• No test is needed because _____ (documentation fix, dependency update, etc.)

Documentation

Usr apps now wait to render form ERB until the app is opened.

Code Authorship & Understanding

• I can explain what this code does and answer questions about it
• This PR was generated or assisted by AI tools (Copilot, Claude, agents). If so, I have reviewed and tested the code
  and I take responsibility for its correctness.

Checklist

• Follows project code style and conventions
• This is a large pull request and was discussed first in an issue or with the maintainers.

Anything else?

No