feat: add restart server action for vendor and tenant

Vendor: POST /api/vendor/tenants/{id}/restart (platform:admin scope)
Tenant: POST /api/tenant/server/restart (tenant:manage scope)

Both call TenantProvisioner.stop() then start() on the server + UI
containers. Restart button on vendor TenantDetailPage (Actions card)
and tenant TenantDashboardPage (Server card). Allowed in any status
including PROVISIONING.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/main/java/net/siegeln/cameleer/saas/portal/TenantPortalController.java

@@ -70,6 +70,12 @@ public class TenantPortalController {
         return ResponseEntity.ok().build();
     }
 
+    @PostMapping("/server/restart")
+    public ResponseEntity<Void> restartServer() {
+        portalService.restartServer();
+        return ResponseEntity.ok().build();
+    }
+
     @GetMapping("/settings")
     public ResponseEntity<TenantPortalService.TenantSettingsData> getSettings() {
         return ResponseEntity.ok(portalService.getSettings());

src/main/java/net/siegeln/cameleer/saas/portal/TenantPortalService.java

@@ -5,6 +5,7 @@ import net.siegeln.cameleer.saas.identity.LogtoManagementClient;
 import net.siegeln.cameleer.saas.identity.ServerApiClient;
 import net.siegeln.cameleer.saas.license.LicenseEntity;
 import net.siegeln.cameleer.saas.license.LicenseService;
+import net.siegeln.cameleer.saas.provisioning.TenantProvisioner;
 import net.siegeln.cameleer.saas.tenant.TenantEntity;
 import net.siegeln.cameleer.saas.tenant.TenantService;
 import org.springframework.stereotype.Service;
@@ -22,15 +23,18 @@ public class TenantPortalService {
     private final LicenseService licenseService;
     private final ServerApiClient serverApiClient;
     private final LogtoManagementClient logtoClient;
+    private final TenantProvisioner tenantProvisioner;
 
     public TenantPortalService(TenantService tenantService,
                                LicenseService licenseService,
                                ServerApiClient serverApiClient,
-                               LogtoManagementClient logtoClient) {
+                               LogtoManagementClient logtoClient,
+                               TenantProvisioner tenantProvisioner) {
         this.tenantService = tenantService;
         this.licenseService = licenseService;
         this.serverApiClient = serverApiClient;
         this.logtoClient = logtoClient;
+        this.tenantProvisioner = tenantProvisioner;
     }
 
     // --- Inner records ---
@@ -160,4 +164,12 @@ public class TenantPortalService {
                 tenant.getServerEndpoint(), tenant.getCreatedAt()
         );
     }
+
+    public void restartServer() {
+        TenantEntity tenant = resolveTenant();
+        if (tenantProvisioner.isAvailable()) {
+            tenantProvisioner.stop(tenant.getSlug());
+            tenantProvisioner.start(tenant.getSlug());
+        }
+    }
 }

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

@@ -109,6 +109,16 @@ public class VendorTenantController {
                 .orElse(ResponseEntity.notFound().build());
     }
 
+    @PostMapping("/{id}/restart")
+    public ResponseEntity<Void> restart(@PathVariable UUID id) {
+        try {
+            vendorTenantService.restartServer(id);
+            return ResponseEntity.ok().build();
+        } catch (IllegalArgumentException e) {
+            return ResponseEntity.notFound().build();
+        }
+    }
+
     @PostMapping("/{id}/suspend")
     public ResponseEntity<TenantResponse> suspend(@PathVariable UUID id,
                                                    @AuthenticationPrincipal Jwt jwt) {

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

@@ -213,6 +213,15 @@ public class VendorTenantService {
         return serverApiClient.getHealth(endpoint);
     }
 
+    public void restartServer(UUID tenantId) {
+        TenantEntity tenant = tenantService.getById(tenantId)
+                .orElseThrow(() -> new IllegalArgumentException("Tenant not found"));
+        if (tenantProvisioner.isAvailable()) {
+            tenantProvisioner.stop(tenant.getSlug());
+            tenantProvisioner.start(tenant.getSlug());
+        }
+    }
+
     @Transactional
     public TenantEntity suspend(UUID tenantId, UUID actorId) {
         TenantEntity tenant = tenantService.getById(tenantId)