feat(archetype): F2.27 — rename soft-deleted name/slug conflicts so creation isn't blocked

[jbourdin]

Problem

Archetype has unique constraints on both name (uniq_archetype_name) and slug (uniq_archetype_slug) at the DB level (src/Entity/Archetype.php:28-29). Soft-deleted rows (deletedAt set, src/Entity/Archetype.php:82-83) still occupy those unique keys, so an admin who deletes an archetype and tries to recreate one with the same name/slug hits a constraint violation. The admin list excludes soft-deletes (['deletedAt' => null] in AdminArchetypeController) so the conflict is invisible from the UI.

Scope

On archetype create (and on update if the new name/slug collides with a soft-deleted row), automatically rename the conflicting soft-deleted row by appending a uniqueness suffix to both its name and slug so the new archetype can take the canonical values.

Suffix shape: __deleted_<short-uniq> — e.g. Gardevoir ex → Gardevoir ex__deleted_a1b2c3 and gardevoir-ex → gardevoir-ex__deleted_a1b2c3. Generate the short id with bin2hex(random_bytes(3)) (6 hex chars, deterministic length) or Symfony\Component\Uid\Ulid truncated — match whatever the codebase already uses.

Recreate-on-create only: don't repurpose this for any other lookup.

Acceptance criteria

• Creating an archetype whose name matches a soft-deleted archetype succeeds; the soft-deleted row is renamed with the suffix on both name and slug.
• Same for slug (e.g. two different display names that slugify to the same value).
• Rename happens in the same transaction as the create — no partial state if the create fails.
• Admin list still shows only non-deleted rows.
• Soft-deleted renamed rows remain restorable for audit (the suffix is appended, the original prefix is preserved for inspection).
• Unit/functional test under tests/ covering: (a) name collision, (b) slug collision via differing names, (c) no collision still works unchanged.
• docs/features.md gains an F2.27 row under §F2.

Key files

• src/Entity/Archetype.php — unique constraints, soft-delete column, PrePersist/PreUpdate slug generator.
• src/Form/ArchetypeFormType.php — current form (no UniqueEntity validator today).
• src/Controller/AdminArchetypeController.php — create/edit flow.
• src/Repository/ArchetypeRepository.php — add a findSoftDeletedByNameOrSlug() helper.
• tests/Entity/ArchetypeTest.php — existing test file to extend.

Notes

• Don't introduce a UniqueEntity Symfony validator before this fix — it would also fire on the soft-deleted row and re-introduce the block at validation time. The rename must happen before the new row is flushed.
• Consider a dedicated ArchetypeNameCollisionResolver service for testability.