Add anonymous builder pattern for test mock objects

Implement anonymous builders following established pattern from
AnonymousApplicationBuilder to reduce test boilerplate and improve
readability. Created 6 builders total (3 in this commit, 3 previously):

New builders in this commit:
- AnonymousMetadataItemBuilder: Simple metadata item mocking
- AnonymousTraceBuilder: Complex trace mocking with SessionMetadata helpers
- AnonymousProjectBuilder: SAST Project interface mocking

Previously committed builders:
- AnonymousSessionMetadataBuilder: Session metadata with MetadataItem lists
- AnonymousScanBuilder: SAST Scan interface mocking with SARIF support
- AnonymousLibraryExtendedBuilder: SCA library mocking with many fields

Refactored test files:
- AssessServiceTest: 20+ trace mocks simplified (SessionMetadata patterns)
- SastServiceTest: All 5 Project and 1 Scan mocks refactored
- SCAServiceTest: All 3 LibraryExtended helper methods refactored

Benefits:
- Reduces 10+ lines of mock setup to 1-3 lines per object
- Lenient stubbing avoids UnnecessaryStubbingException
- Fluent API improves test readability
- Convenience methods simplify complex nested object creation

All 278 tests pass. Addresses mcp-hyj.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ChrisEdwards

src/test/java/com/contrast/labs/ai/mcp/contrast/AnonymousMetadataItemBuilder.java

@@ -0,0 +1,62 @@
+package com.contrast.labs.ai.mcp.contrast;
+
+import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.mock;
+
+import com.contrastsecurity.models.MetadataItem;
+import java.util.UUID;
+
+/**
+ * Builder for creating anonymous MetadataItem mocks with sensible defaults. Only override fields
+ * that matter for your specific test.
+ *
+ * <p>Example usage:
+ *
+ * <pre>
+ * MetadataItem item = AnonymousMetadataItemBuilder.validMetadataItem()
+ *     .withDisplayLabel("ENVIRONMENT")
+ *     .withValue("PRODUCTION")
+ *     .build();
+ * </pre>
+ */
+public class AnonymousMetadataItemBuilder {
+  private final MetadataItem metadataItem;
+  private String displayLabel = "Label-" + UUID.randomUUID().toString().substring(0, 8);
+  private String agentLabel = "agentLabel-" + UUID.randomUUID().toString().substring(0, 8);
+  private String value = "Value-" + UUID.randomUUID().toString().substring(0, 8);
+
+  private AnonymousMetadataItemBuilder() {
+    this.metadataItem = mock(MetadataItem.class);
+  }
+
+  /** Create a builder with valid defaults for all required fields. */
+  public static AnonymousMetadataItemBuilder validMetadataItem() {
+    return new AnonymousMetadataItemBuilder();
+  }
+
+  public AnonymousMetadataItemBuilder withDisplayLabel(String displayLabel) {
+    this.displayLabel = displayLabel;
+    return this;
+  }
+
+  public AnonymousMetadataItemBuilder withAgentLabel(String agentLabel) {
+    this.agentLabel = agentLabel;
+    return this;
+  }
+
+  public AnonymousMetadataItemBuilder withValue(String value) {
+    this.value = value;
+    return this;
+  }
+
+  /**
+   * Build the MetadataItem mock with all configured values. Uses lenient stubbing to avoid
+   * UnnecessaryStubbingException for fields not accessed in specific tests.
+   */
+  public MetadataItem build() {
+    lenient().when(metadataItem.getDisplayLabel()).thenReturn(displayLabel);
+    lenient().when(metadataItem.getAgentLabel()).thenReturn(agentLabel);
+    lenient().when(metadataItem.getValue()).thenReturn(value);
+    return metadataItem;
+  }
+}

src/test/java/com/contrast/labs/ai/mcp/contrast/AnonymousProjectBuilder.java

@@ -0,0 +1,153 @@
+package com.contrast.labs.ai.mcp.contrast;
+
+import static org.mockito.Mockito.lenient;
+import static org.mockito.Mockito.mock;
+
+import com.contrastsecurity.sdk.scan.Project;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.UUID;
+
+/**
+ * Builder for creating anonymous Project mocks with sensible defaults. Only override fields that
+ * matter for your specific test.
+ *
+ * <p>Note: Project is an interface, so this builder mocks the interface methods (not getters).
+ *
+ * <p>Example usage:
+ *
+ * <pre>
+ * Project project = AnonymousProjectBuilder.validProject()
+ *     .withName("MyProject")
+ *     .withId("project-123")
+ *     .build();
+ * </pre>
+ */
+public class AnonymousProjectBuilder {
+  private final Project project;
+  private String id = "project-" + UUID.randomUUID().toString().substring(0, 8);
+  private String name = "Project-" + UUID.randomUUID().toString().substring(0, 8);
+  private String organizationId = "org-" + UUID.randomUUID().toString().substring(0, 8);
+  private String language = "Java";
+  private boolean archived = false;
+  private int critical = 0;
+  private int high = 0;
+  private int medium = 0;
+  private int low = 0;
+  private int note = 0;
+  private String lastScanId = "scan-" + UUID.randomUUID().toString().substring(0, 8);
+  private Instant lastScanTime = Instant.now();
+  private int completedScans = 1;
+  private Collection<String> includeNamespaceFilters = new ArrayList<>();
+  private Collection<String> excludeNamespaceFilters = new ArrayList<>();
+
+  private AnonymousProjectBuilder() {
+    this.project = mock(Project.class);
+  }
+
+  /** Create a builder with valid defaults for all required fields. */
+  public static AnonymousProjectBuilder validProject() {
+    return new AnonymousProjectBuilder();
+  }
+
+  public AnonymousProjectBuilder withId(String id) {
+    this.id = id;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withName(String name) {
+    this.name = name;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withOrganizationId(String organizationId) {
+    this.organizationId = organizationId;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withLanguage(String language) {
+    this.language = language;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withArchived(boolean archived) {
+    this.archived = archived;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withCritical(int critical) {
+    this.critical = critical;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withHigh(int high) {
+    this.high = high;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withMedium(int medium) {
+    this.medium = medium;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withLow(int low) {
+    this.low = low;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withNote(int note) {
+    this.note = note;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withLastScanId(String lastScanId) {
+    this.lastScanId = lastScanId;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withLastScanTime(Instant lastScanTime) {
+    this.lastScanTime = lastScanTime;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withCompletedScans(int completedScans) {
+    this.completedScans = completedScans;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withIncludeNamespaceFilters(
+      Collection<String> includeNamespaceFilters) {
+    this.includeNamespaceFilters = includeNamespaceFilters;
+    return this;
+  }
+
+  public AnonymousProjectBuilder withExcludeNamespaceFilters(
+      Collection<String> excludeNamespaceFilters) {
+    this.excludeNamespaceFilters = excludeNamespaceFilters;
+    return this;
+  }
+
+  /**
+   * Build the Project mock with all configured values. Uses lenient stubbing to avoid
+   * UnnecessaryStubbingException for fields not accessed in specific tests.
+   */
+  public Project build() {
+    lenient().when(project.id()).thenReturn(id);
+    lenient().when(project.name()).thenReturn(name);
+    lenient().when(project.organizationId()).thenReturn(organizationId);
+    lenient().when(project.language()).thenReturn(language);
+    lenient().when(project.archived()).thenReturn(archived);
+    lenient().when(project.critical()).thenReturn(critical);
+    lenient().when(project.high()).thenReturn(high);
+    lenient().when(project.medium()).thenReturn(medium);
+    lenient().when(project.low()).thenReturn(low);
+    lenient().when(project.note()).thenReturn(note);
+    lenient().when(project.lastScanId()).thenReturn(lastScanId);
+    lenient().when(project.lastScanTime()).thenReturn(lastScanTime);
+    lenient().when(project.completedScans()).thenReturn(completedScans);
+    lenient().when(project.includeNamespaceFilters()).thenReturn(includeNamespaceFilters);
+    lenient().when(project.excludeNamespaceFilters()).thenReturn(excludeNamespaceFilters);
+    return project;
+  }
+}