Improve Trader V4 training pipeline

Align entry labels with max future edge, tune direction labeling, and harden regression evaluation.

Add training diagnostics, price-plan search, feature screening, and nonlinear benchmark scripts.

src/main/java/com/quantai/trader/artifact/TraderArtifactLoader.java

@@ -29,7 +29,7 @@ import java.util.stream.StreamSupport;
 public class TraderArtifactLoader {
     private static final Logger log = LoggerFactory.getLogger(TraderArtifactLoader.class);
     private static final Set<String> REQUIRED_MODELS = Set.of("DIRECTION", "ENTRY", "CONTINUE", "EXIT", "RISK");
-    private static final int REQUIRED_FEATURE_COUNT = 39;
+    private static final int REQUIRED_FEATURE_COUNT = 54;
     private static final int REQUIRED_ONNX_OPSET_VERSION = 17;
     private static final Map<String, Set<String>> REQUIRED_OUTPUT_MAPPING_KEYS = Map.of(
             "DIRECTION", Set.of("long_prob", "short_prob", "neutral_prob"),

src/main/java/com/quantai/trader/feature/TraderFeatureVectorBuilder.java

@@ -27,7 +27,7 @@ import java.util.stream.StreamSupport;
 @Component
 public class TraderFeatureVectorBuilder {
     private static final Logger log = LoggerFactory.getLogger(TraderFeatureVectorBuilder.class);
-    private static final int REQUIRED_FEATURE_COUNT = 39;
+    private static final int REQUIRED_FEATURE_COUNT = 54;
 
     private final TraderProperties properties;
     private final ObjectMapper objectMapper;