Fix database access warning during app initialization with Django 5

[gagelarsen]

Description

This merge request addresses the RuntimeWarning: Accessing the database during app initialization is discouraged warning that Django 5 emits when starting the development server with tethys manage start. There were three sources of database access while apps.ready is False:

1. tethys_apps/admin.py built the dynamic group admin form at import time (admin autodiscovery runs during app initialization), iterating TethysApp.objects.all() and querying GroupObjectPermission.
2. App harvesting in TethysAppsConfig.ready() syncs apps/extensions (and cookies) with the database by design.
3. TethysQuotasConfig.ready() syncs resource quota handlers with the database by design.

Changes Made to Code

• tethys_apps/admin.py: CustomGroup now creates the GOP app access form lazily in get_form() instead of at registration/import time (as suggested in the issue comments), so no queries run during app initialization. If the database isn't migrated yet, it logs a warning and falls back to the default GroupAdmin form. As a side benefit, the form now reflects the currently installed apps on every request.
• tethys_apps/apps.py and tethys_quotas/apps.py: the database syncing done in ready() is intentional, so Django's app-initialization RuntimeWarning is suppressed around exactly those calls (scoped with warnings.catch_warnings() and matched by message + category).
• Added/updated unit tests: registration executes zero queries (CaptureQueriesContext), get_form() builds the dynamic per-app fields and degrades gracefully on ProgrammingError, and both ready() methods suppress the warning (skipped on Django < 5.0 where the warning doesn't exist).

Verified end-to-end: tethys manage start previously displayed the warning (45 init-time queries flagged with -W always); with this change it starts with zero warnings, and the Group admin add/change/save pages work with all dynamic per-app fields.

Related PRs, Issues, and Discussions

• Fixes [BUG] Warning during tethys manage start when using Django 5.0 #1060

Additional Notes

• The suppression is scoped tightly: only RuntimeWarnings matching Django's app-initialization message, only around the intentional sync calls, and filter state is restored afterward.

Quality Checks

• At least one new test has been written for new code
• New code has 100% test coverage
• Code has been formatted with Black
• Code has been linted with flake8
• Docstrings for new methods have been added
• The documentation has been updated appropriately

🤖 Generated with Claude Code

[coveralls]

coverage: 100.0%. remained the same — fix-db-access-warning-1060 into main