feat(13-03): wire 4 Phase 13 sources into RegisterAll (32 total)

- Register DockerHub, Kubernetes, Terraform, Helm as credentialless sources
- Update RegisterAll tests and integration test to expect 32 sources

pkg/recon/sources/integration_test.go

@@ -524,8 +524,8 @@ func TestRegisterAll_Phase12(t *testing.T) {
 	})
 
 	names := eng.List()
-	if n := len(names); n != 28 {
-		t.Fatalf("expected 28 sources from RegisterAll, got %d: %v", n, names)
+	if n := len(names); n != 32 {
+		t.Fatalf("expected 32 sources from RegisterAll, got %d: %v", n, names)
 	}
 
 	// Build lookup for source access.