test(perm): shared helpers for legacy-only holders & grantless members

[vecchp]

Summary

Consolidates the legacy-only fixture dance the grant cutover left copy-pasted across suites — create a leftover PermissionGroup row (nothing provisions grant-only templates any more), add a membership, drop the auto-mirrored Grant — into shared helpers, and adopts them everywhere.

Stacks on #2450 (feat/perm/teams-header-strip); lands after it.

What changes

New helpers (common/tests/utils.py)

• make_permission_group(*, organization, template_name) — the org's PermissionGroup, created on demand (idempotent template + row).
• revoke_grants(user) — drop every Grant for the user: the grantless-org-member state.
• add_legacy_membership(user, *, group) — legacy membership without the Grant mirror (m2m-edge mirror dropped).
• make_legacy_only_holder(*, organization, template_name, user) — the composite: org membership + leftover group + no Grants.

Adopted in

• teams / reports / member-management test_grant_authorization suites (each lost its inline template/group/mirror block);
• accounts/tests/test_roles.py — its local _add_legacy_membership and _legacy_org_admin_group copies are gone;
• accounts/tests/test_role_manager_grants.py, accounts/tests/test_permission_group.py — make_permission_group;
• shelters test_room_queries / test_bed_queries / test_reservation_queries — revoke_grants(self.operator) replaces the inline Grant…delete().

Test plan

• accounts common reports teams shelters — 1310 passed; ruff clean.
• No production code touched (test utilities only).

Summary by Sourcery

Centralize legacy permission and grantless-member test fixtures and adopt them across the affected test suites.

New Features:

• Add shared test helpers for creating permission groups, modeling legacy-only memberships, and removing user grants.

Enhancements:

• Consolidate duplicated legacy permission fixture setup across account, team, report, member-management, and shelter tests.

Tests:

• Update authorization, role, permission-group, and shelter query tests to use the shared helpers.

[sourcery-ai]

Sorry @vecchp, you've used your own review budget of 250,000 diff characters for the last 7 days.

You can request another review in 4 days and 22 hours by commenting @sourcery-ai review. Upgrade to get a review now.

[sourcery-ai]

Reviewer's Guide

This test-only PR consolidates legacy permission-group and grantless-member fixture setup into reusable helpers, then applies them across authorization, role-backfill, permission-group, and shelter query suites without changing production code.

File-Level Changes

Change	Details	Files
Centralize construction of legacy-only permission fixtures and grantless users.	Add idempotent permission-group creation by organization and template. Add helpers to remove all user grants and create group membership without the signal-generated Grant mirror. Add a composite helper for organization members with leftover legacy groups and no grants.	apps/betterangels-backend/common/tests/utils.py
Replace duplicated legacy-only authorization fixtures with shared setup across authorization and role migration tests.	Adopt the composite helper in teams, reports, and member-management denial tests. Replace local legacy membership and group-building helpers in role backfill tests. Use shared group creation in permission-group and role-manager grant tests.	apps/betterangels-backend/accounts/tests/test_member_management_grant_authorization.py apps/betterangels-backend/accounts/tests/test_roles.py apps/betterangels-backend/accounts/tests/test_role_manager_grants.py apps/betterangels-backend/accounts/tests/test_permission_group.py apps/betterangels-backend/reports/tests/test_grant_authorization.py apps/betterangels-backend/teams/tests/test_grant_authorization.py
Standardize grant removal in shelter query tests.	Replace inline Grant deletion with the shared revoke_grants helper in room, bed, and reservation query tests.	apps/betterangels-backend/shelters/tests/test_room_queries.py apps/betterangels-backend/shelters/tests/test_bed_queries.py apps/betterangels-backend/shelters/tests/test_reservation_queries.py

---

Tips and commands

Interacting with Sourcery

• Trigger a new review: Comment @sourcery-ai review on the pull request.
• Continue discussions: Reply directly to Sourcery's review comments.
• Generate a GitHub issue from a review comment: Ask Sourcery to create an
  issue from a review comment by replying to it. You can also reply to a
  review comment with @sourcery-ai issue to create an issue from it.
• Generate a pull request title: Write @sourcery-ai anywhere in the pull
  request title to generate a title at any time. You can also comment
  @sourcery-ai title on the pull request to (re-)generate the title at any time.
• Generate a pull request summary: Write @sourcery-ai summary anywhere in
  the pull request body to generate a PR summary at any time exactly where you
  want it. You can also comment @sourcery-ai summary on the pull request to
  (re-)generate the summary at any time.
• Generate reviewer's guide: Comment @sourcery-ai guide on the pull
  request to (re-)generate the reviewer's guide at any time.
• Resolve all Sourcery comments: Comment @sourcery-ai resolve on the
  pull request to resolve all Sourcery comments. Useful if you've already
  addressed all the comments and don't want to see them anymore.
• Dismiss all Sourcery reviews: Comment @sourcery-ai dismiss on the pull
  request to dismiss all existing Sourcery reviews. Especially useful if you
  want to start fresh with a new review - don't forget to comment
  @sourcery-ai review to trigger a new review!

Customizing Your Experience

Access your dashboard to:

• Enable or disable review features such as the Sourcery-generated pull request
  summary, the reviewer's guide, and others.
• Change the review language.
• Add, remove or edit custom review instructions.
• Adjust other review settings.

Getting Help

• Contact our support team for questions or feedback.
• Visit our documentation for detailed guides and information.
• Keep in touch with the Sourcery team by following us on X/Twitter, LinkedIn or GitHub.