feat: create per-tenant PG database during provisioning, drop on delete

Inject TenantDatabaseService; call createTenantDatabase() at the start
of provisionAsync() (stores generated password on TenantEntity), and
dropTenantDatabase() in delete() before GDPR data erasure.

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

src/main/java/net/siegeln/cameleer/saas/vendor/VendorTenantService.java

@@ -6,6 +6,7 @@ import net.siegeln.cameleer.saas.identity.LogtoConfig;
 import net.siegeln.cameleer.saas.identity.LogtoManagementClient;
 import net.siegeln.cameleer.saas.identity.ServerApiClient;
 import net.siegeln.cameleer.saas.provisioning.ProvisioningProperties;
+import net.siegeln.cameleer.saas.provisioning.TenantDatabaseService;
 import net.siegeln.cameleer.saas.provisioning.TenantDataCleanupService;
 import net.siegeln.cameleer.saas.identity.ServerApiClient.ServerHealthResponse;
 import net.siegeln.cameleer.saas.license.LicenseEntity;
@@ -47,6 +48,7 @@ public class VendorTenantService {
     private final AuditService auditService;
     private final ProvisioningProperties provisioningProps;
     private final TenantDataCleanupService dataCleanupService;
+    private final TenantDatabaseService tenantDatabaseService;
 
     public VendorTenantService(TenantService tenantService,
                                TenantRepository tenantRepository,
@@ -57,7 +59,8 @@ public class VendorTenantService {
                                LogtoConfig logtoConfig,
                                AuditService auditService,
                                ProvisioningProperties provisioningProps,
-                               TenantDataCleanupService dataCleanupService) {
+                               TenantDataCleanupService dataCleanupService,
+                               TenantDatabaseService tenantDatabaseService) {
         this.tenantService = tenantService;
         this.tenantRepository = tenantRepository;
         this.licenseService = licenseService;
@@ -68,6 +71,7 @@ public class VendorTenantService {
         this.auditService = auditService;
         this.provisioningProps = provisioningProps;
         this.dataCleanupService = dataCleanupService;
+        this.tenantDatabaseService = tenantDatabaseService;
     }
 
     @Transactional
@@ -119,7 +123,30 @@ public class VendorTenantService {
     @Async
     public void provisionAsync(UUID tenantId, String slug, String tier, String licenseToken, UUID actorId) {
         try {
-            var provisionRequest = new TenantProvisionRequest(tenantId, slug, tier, licenseToken);
+            // Create per-tenant PG user + schema
+            String dbPassword = java.util.UUID.randomUUID().toString().replace("-", "")
+                    + java.util.UUID.randomUUID().toString().replace("-", "").substring(0, 8);
+            try {
+                tenantDatabaseService.createTenantDatabase(slug, dbPassword);
+            } catch (Exception e) {
+                log.error("Failed to create tenant database for {}: {}", slug, e.getMessage(), e);
+                tenantRepository.findById(tenantId).ifPresent(t -> {
+                    t.setProvisionError("Database setup failed: " + e.getMessage());
+                    tenantRepository.save(t);
+                });
+                return;
+            }
+
+            // Store DB password on entity
+            TenantEntity tenantForDb = tenantRepository.findById(tenantId).orElse(null);
+            if (tenantForDb == null) {
+                log.error("Tenant {} disappeared during provisioning", slug);
+                return;
+            }
+            tenantForDb.setDbPassword(dbPassword);
+            tenantRepository.save(tenantForDb);
+
+            var provisionRequest = new TenantProvisionRequest(tenantId, slug, tier, licenseToken, dbPassword);
             ProvisionResult result = tenantProvisioner.provision(provisionRequest);
 
             TenantEntity tenant = tenantRepository.findById(tenantId).orElse(null);
@@ -302,7 +329,15 @@ public class VendorTenantService {
             }
         }
 
+        // Drop per-tenant PG user + database
+        try {
+            tenantDatabaseService.dropTenantDatabase(tenant.getSlug());
+        } catch (Exception e) {
+            log.warn("Failed to drop tenant database for {}: {}", tenant.getSlug(), e.getMessage());
+        }
+
         // Erase tenant data from server databases (GDPR)
+        // TODO: split into cleanupClickHouse() in next task
         dataCleanupService.cleanup(tenant.getSlug());
 
         // Soft-delete