[#SIRH-17] Ajouter un système de log des actions utilisateurs (#9)

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## Description de la PR

## Modification du .env

## Check list

- [ ] Pas de régression
- [ ] TU/TI/TF rédigée
- [ ] TU/TI/TF OK
- [ ] CHANGELOG modifié

Reviewed-on: #9
Co-authored-by: tristan <tristan@yuno.malio.fr>
Co-committed-by: tristan <tristan@yuno.malio.fr>

CLAUDE.md

@@ -72,6 +72,12 @@
 - File uploads: `deserialize: false` on Post, access file via RequestStack
 - Upload dir: `%kernel.project_dir%/var/uploads`
 
+## Audit Logging
+- All processors that modify entities impacting calculations (heures, absences, contrats, RTT) MUST inject `AuditLogger` and log create/update/delete actions
+- `AuditLogger::log()` persists without flushing — the processor's `flush()` handles both the data change and the audit entry atomically
+- Audit logs are accessible only via `ROLE_SUPER_ADMIN` (hidden role, added manually in DB)
+- Documentation: `doc/audit-logging.md`
+
 ## Backend Conventions
 - Prefer explicit DTOs over associative arrays
 - Business rules in backend (providers/processors/services), frontend is display/interaction only