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/MembreDashboardResource.java

@@ -24,7 +24,7 @@ public class MembreDashboardResource {
 
     @GET
     @Path("/me")
-    @RolesAllowed({ "USER", "MEMBRE", "ADMIN", "SUPER_ADMIN" })
+    @RolesAllowed({ "USER", "MEMBRE", "ADMIN", "ADMIN_ORGANISATION", "SUPER_ADMIN" })
     @Operation(summary = "Récupérer la synthèse du dashboard pour le membre connecté")
     public Response getMonDashboard() {
         MembreDashboardSyntheseResponse data = dashboardService.getDashboardData();