fix: fetch actual agent/environment counts from server for tenant dashboard

The dashboard was showing hardcoded zeroes for agent and environment usage.
Now fetches real counts via M2M API from the tenant's server.

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

src/test/java/net/siegeln/cameleer/saas/portal/TenantPortalServiceTest.java

@@ -104,6 +104,8 @@ class TenantPortalServiceTest {
 
         when(tenantService.getById(tenantId)).thenReturn(Optional.of(tenant));
         when(serverApiClient.getHealth("http://server:8080")).thenReturn(new ServerHealthResponse(true, "UP"));
+        when(serverApiClient.getAgentCount("http://server:8080")).thenReturn(3);
+        when(serverApiClient.getEnvironmentCount("http://server:8080")).thenReturn(1);
         when(licenseService.getActiveLicense(tenantId)).thenReturn(Optional.of(license));
 
         var result = tenantPortalService.getDashboard();
@@ -119,6 +121,8 @@ class TenantPortalServiceTest {
         assertThat(result.licenseDaysRemaining()).isGreaterThanOrEqualTo(29);
         assertThat(result.limits()).isNotEmpty();
         assertThat(result.features()).isNotEmpty();
+        assertThat(result.agentCount()).isEqualTo(3);
+        assertThat(result.environmentCount()).isEqualTo(1);
     }
 
     @Test
@@ -136,6 +140,8 @@ class TenantPortalServiceTest {
         assertThat(result.serverEndpoint()).isNull();
         assertThat(result.licenseTier()).isNull();
         assertThat(result.licenseDaysRemaining()).isZero();
+        assertThat(result.agentCount()).isZero();
+        assertThat(result.environmentCount()).isZero();
     }
 
     // --- getLicense tests ---