feat: BackupService real pg_dump, OrganisationService region stats, SystemConfigService overrides

- BackupService: DB-persisted metadata (BackupRecord/BackupConfig entities + V16 Flyway migration),
  real pg_dump execution via ProcessBuilder, soft-delete on deleteBackup, pg_restore manual guidance
- OrganisationService: repartitionRegion now queries Adresse entities (was Map.of() stub)
- SystemConfigService: in-memory config overrides via AtomicReference (no DB dependency)
- SystemMetricsService: null-guard on MemoryMXBean in getSystemStatus() (fixes test NPE)
- Souscription workflow: SouscriptionService, SouscriptionResource, FormuleAbonnementRepository,
  V11 Flyway migration, admin REST clients
- Flyway V8-V15: notes membres, types référence, type orga constraint, seed roles,
  première connexion, Wave checkout URL, Wave telephone column length fix
- .gitignore: added uploads/ and .claude/

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main/java/dev/lions/unionflow/server/resource/TicketResource.java

@@ -29,7 +29,7 @@ import java.util.UUID;
 @Consumes(MediaType.APPLICATION_JSON)
 @Tag(name = "Tickets", description = "Gestion des tickets support")
 @Slf4j
-@RolesAllowed({ "USER", "ADMIN", "MEMBRE" })
+@RolesAllowed({ "USER", "ADMIN", "ADMIN_ORGANISATION", "MEMBRE" })
 public class TicketResource {
 
     @Inject