[codex] Fix ballin_update output spacing

[JBallin]

Summary

• remove the unconditional blank line that ballin_update printed before setup output
• print the first-run analytics notice as its own paragraph after setup/docs output
• tighten output assertions for ballin_update and setup analytics notice spacing

Root cause

ballin_update always printed an empty line before invoking setup, even when setup had no immediate output. Separately, analytics setup wrote the notice directly through the generic line writer, so it could appear immediately after the previous setup/docs line instead of as a separated notice block.

Validation

• npm run test:unit -- test/ballin_update.test.ts test/install_setup.test.ts
• npm test