chore: address Eclipse warnings and improve null safety

[david-waltermire]

Summary

This PR addresses Eclipse IDE warnings across all modules, improves null safety throughout the codebase, and enhances the code generator with better validation and diagnostics.

Changes

CLI Processor Module

• CallingContext.java: Wrap Optional.of() and Optional.empty() returns with ObjectUtils.notNull()
• ShellCompletionCommand.java: Wrap List.get() and Path.of() returns for null safety
• CompletionScriptGenerator.java: Wrap StringBuilder.toString() and String.replaceAll() returns
• CompletionTypeRegistry.java: Wrap Collectors.joining() result

Core Module

• DynamicContext.java: Remove unused imports
• JsonPointerFormatter.java: Remove unused imports
• NodeItemTraversalTest.java: Wrap URI.create() calls with ObjectUtils.notNull()
• Various test files: Add assertNotNull checks and remove unused imports

Databind Module

Code Generator Enhancements

• AbstractPropertyTypeInfo.java:
  • Add introspection to detect methods declared in superinterfaces
  • Generate @Override annotations for getters/setters that override interface methods
  • Check base class and superinterfaces via reflection
• DefaultMetaschemaClassFactory.java:
  • Add extendsIBoundObject() helper to check if interfaces extend IBoundObject
  • Omit redundant IBoundObject interface when a superinterface already extends it
• DefaultBindingConfiguration.java:
  • Restore null check for groupAsName (fixes NPE with ConcurrentHashMap)
  • Add logging warnings for bindings missing both name and target attributes
  • Add descriptive error messages to Objects.requireNonNull() calls
• ClassUtils.java: Remove redundant assert on caught exception
• ChoiceGroupTypeInfoImpl.java: Add null-safe Javadoc generation for item types

Binding Model Improvements

• InstanceModelGroupedFieldInline.java: Add null check for flagName before IEnhancedQName.of()
• Generated binding classes: Wrap collection and toString returns with ObjectUtils.notNull()

Schemagen Module

• IXmlGenerationState.java: New interface to break circular dependency
• XmlDatatypeManager.java: Add public constants for XML Schema namespace/prefix
• XmlGenerationState.java: Implement new interface
• Update type generation classes to use interface instead of concrete class

Eclipse Configuration

• Disable annotation processing (aptEnabled=false) across all modules
• Update .gitignore to include Eclipse JDT APT preferences

Documentation

• Add "Classpath Requirements for Code Generation" section to .claude/skills/metaschema-java-library.md:
  • How the generator uses reflection for method override detection
  • Maven plugin dependency configuration example
  • Behavior when classes aren't on classpath during code generation
  • Multi-module project considerations

Review Feedback Addressed

1. DefaultBindingConfiguration.java:

   • Restore null check for groupAsName (NPE prevention)
   • Replace assert with Objects.requireNonNull() for interface names
   • Add descriptive error messages for null checks
   • Add logging warnings for skipped bindings

2. InstanceModelGroupedFieldInline.java:

   • Add null check for flagName before IEnhancedQName.of() call

3. BoundChoiceTest.java:

   • Move assertNotNull outside lambda for clearer error messages

Test plan

• All tests pass with mvn test
• Build succeeds with mvn install -PCI -Prelease
• Eclipse warnings resolved

Summary by CodeRabbit

• Refactor

  • Improved null-safety and resource/ownership handling across the project for more robust runtime and test behavior.

• New Features

  • Added public helper APIs and utilities to simplify schema/code generation, databind operations, and test support.

• Documentation

  • Extensive Javadoc, package docs, and docs updates; new PRD entries added (one completed, one in progress).

• Chores

  • Standardized IDE/formatter preferences and updated ignore rules to include a previously excluded IDE prefs file.

_{✏️ Tip: You can customize this high-level summary in your review settings.}