rPc49eeb235ea0

Improve command line prompts in setup issue pages

Summary:
This is a follow-up to D25425, where these improvements to the CLI prompt markers were discussed.

Changes included in this revision:

- Build all prompts the same way
- Remove space after the prompt marker (add it via CSS instead)
- Add server path prefix
- Make the prompt unselectable

Test Plan:
- Visit any of the setup issue pages, e.g. <PHORGE_URL>/config/issue/auth.config-unlocked/ (after ensuring that the corresponding issue is present — in…