Bug/maintenance mode

[mabiede]

No description provided.

[Copilot]

Pull request overview

This PR refactors tenant maintenance mode handling by moving the maintenance toggle into a dedicated update flow, improving the maintenance-mode UI, and adjusting migrations and tenant event handling to support the new behavior.

Changes:

• Move the tenant maintenance toggle out of the general “edit tenant details” form into a dedicated “update maintenance” form + route + handler.
• Add a dedicated maintenance-mode page layout and show it from tenant middleware when a tenant is in maintenance-related states.
• Introduce a dedicated CQRS command + tests for maintenance toggling, and adjust tenant events/types accordingly.

Reviewed changes

Copilot reviewed 17 out of 18 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pool/web/view/page/page_utils.ml	Adds a dedicated maintenance page utility (title + illustration + text).
pool/web/view/page/page_root_tenant.ml	Adds a status column in the tenant list and introduces a separate maintenance form on tenant detail.
pool/web/middleware/middleware_tenant.ml	Fixes request-handling flow and switches maintenance response to the new maintenance page utility.
pool/web/handler/root_tenant_update.ml	Removes maintenance handling from detail updates and adds a dedicated update_maintenance handler.
pool/test/tenant_test.ml	Updates the existing “update tenant details” test and adds a new “update tenant maintenance” test.
pool/test/command.ml	Registers the new tenant maintenance command test case.
pool/routes/routes.ml	Adds a new POST route for /update-maintenance.
pool/cqrs_command/pool_tenant_command.ml	Removes maintenance toggle from EditDetails and adds UpdateMaintenance command.
pool/app/pool_tenant/pool_tenant.mli	Adjusts tenant update/event types for the maintenance refactor.
pool/app/pool_tenant/event.ml	Updates event handling for maintenance events and removes status changes from DetailsEdited.
pool/app/pool_database/root.ml	Registers several migrations as root-only steps.
pool/app/pool_database/migrations/migration_202503130858.ml	Adds migration_root variant and minor SQL formatting cleanup.
pool/app/pool_database/migrations/migration_202503061915.ml	Adds migration_root variant.
pool/app/pool_database/migrations/migration_202502271318.ml	Adds migration_root variant.
pool/app/pool_common/locales/i18n_en.ml	Updates English maintenance text.
pool/app/pool_common/locales/i18n_de.ml	Updates German maintenance text.
CHANGELOG.md	Notes the maintenance toggle fix on the root tenant page.