addressed feedback

Author: leandroberetta

docs/api.md

@@ -328,13 +328,6 @@ Following is the supported API format for writing to loki:
          grpcConfig: gRPC client configuration (used only for gRPC client type)
              keepAlive: keep alive interval
              keepAliveTimeout: keep alive timeout
-             tls: TLS configuration
-                 enabled: enable TLS
-                 certFile: path to client certificate file
-                 keyFile: path to client key file
-                 caFile: path to CA certificate file
-                 serverName: server name for certificate verification
-                 insecureSkipVerify: skip certificate verification (insecure)
 </pre>
 ## Write Standard Output
 Following is the supported API format for writing to standard output:

pkg/api/write_loki.go

@@ -91,7 +91,10 @@ func (w *WriteLoki) SetDefaults() {
 	}
 
 	// Set defaults for gRPC config if gRPC client protocol is selected
-	if w.ClientProtocol == "grpc" && w.GRPCConfig != nil {
+	if w.ClientProtocol == "grpc" {
+		if w.GRPCConfig == nil {
+			w.GRPCConfig = &GRPCLokiConfig{}
+		}
 		w.GRPCConfig.SetDefaults()
 	}
 }

pkg/pipeline/write/write_loki_test.go

@@ -452,7 +452,7 @@ func TestBuildGRPCLokiConfig(t *testing.T) {
 				TenantID:       "test-tenant",
 				GRPCConfig:     nil,
 			},
-			wantErr: true,
+			wantErr: true, // buildGRPCLokiConfig validates directly (SetDefaults not called in this unit test)
 		},
 		{
 			name: "invalid duration in gRPC config",
@@ -601,14 +601,13 @@ func TestWriteLokiValidation(t *testing.T) {
 			errMsg:  "url can't be empty",
 		},
 		{
-			name: "missing gRPC config",
+			name: "auto-created gRPC config with defaults",
 			config: &api.WriteLoki{
 				URL:            "localhost:9095",
 				ClientProtocol: "grpc",
 				BatchSize:      1024,
 			},
-			wantErr: true,
-			errMsg:  "grpcConfig is required",
+			wantErr: false, // SetDefaults will auto-create GRPCConfig
 		},
 		{
 			name: "invalid batch size",