Description

• Fixes a UX gap on Linux/WSL where astro dev start (standalone mode) reports "Airflow is ready!" but never tells the user how to log in. AF2 uses FAB auth, and on Linux upstream airflow standalone generates a random admin password into $AIRFLOW_HOME/standalone_admin_password.txt — users hit the login screen, guess admin/admin, and get "Invalid login."
• Adds printLoginHint() to the standalone startup output. Prints:
  • AF2 macOS → Login: admin / admin (matches the Darwin shim's seeded credentials)
  • AF2 Linux/WSL → Login: username admin, password in .astro/standalone/standalone_admin_password.txt
  • AF3 → nothing (Simple Auth Manager accepts any username, no hint needed)
• Wired into both startForeground and startBackground paths so the hint appears whether the user runs with or without -f.

🎟 Issue(s)

Related #XXX

🧪 Functional Testing

Tested locally on both MacOS and Linux:

• Linux

astro dev start --standalone
Note: Standalone mode is experimental. Report issues at https://github.com/astronomer/astro-cli/issues

✔ Environment ready

Starting Airflow in standalone mode…

✔ Airflow is ready! (PID 90711)
➤ Airflow UI: http://af2.localhost:6563/
➤ View logs: astro dev logs -f
➤ Stop:      astro dev stop
➤ Login:      username admin, password in .astro/standalone/standalone_admin_password.txt

• MacOS

astro dev start --standalone
Note: Standalone mode is experimental. Report issues at https://github.com/astronomer/astro-cli/issues

✔ Environment ready

Starting Airflow in standalone mode…

✔ Airflow is ready! (PID 75754)
➤ Airflow UI: http://af2.localhost:6563
➤ View logs: astro dev logs -f
➤ Stop:      astro dev stop
➤ Login:      admin / admin

📸 Screenshots

Add screenshots to illustrate the validity of these changes.

📋 Checklist

• Rebased from the main (or release if patching) branch (before testing)
• Ran make test before taking out of draft
• Ran make lint before taking out of draft
• Added/updated applicable tests
• Tested against Astro-API (if necessary).
• Tested against Houston-API and Astronomer (if necessary).
• Communicated to/tagged owners of respective clients potentially impacted by these changes.
• Updated any related documentation