Add macOS 15 CI target and fix ARM i8mm feature conflict

[bernardladenthin]

Summary

This PR adds comprehensive unit tests for the Pair generic utility class and introduces developer documentation to guide contributors working with the codebase.

Key Changes

• Added PairTest.java: Comprehensive test suite with 18 test cases covering:

  • Basic getter functionality (getKey(), getValue())
  • Null handling for both key and value
  • Equality semantics (same pairs, different keys/values, null comparisons, type mismatches, self-equality)
  • Hash code consistency and null safety
  • String representation with various input types
  • Generic type support with different type combinations (primitives, arrays, complex types)

• Added CLAUDE.md: Developer guidance document including:

  • Project overview and architecture explanation
  • Build commands for Java (Maven) and native C++ (CMake) components
  • Detailed architecture description of the two-layer design (Java/Native)
  • Parameter flow and native library resolution mechanisms
  • Testing requirements and setup
  • Key constraints and best practices

• Updated CI workflow: Added macOS 15 runner support with appropriate CMake flags (-DGGML_NATIVE=OFF) and improved artifact naming to be runner-specific for better debugging.

Implementation Details

The PairTest class uses JUnit 4 and covers edge cases including null values, type safety with generics, and proper equals() and hashCode() contract compliance. The test suite ensures the Pair utility class is robust for use throughout the codebase.

The CLAUDE.md file serves as a reference guide for understanding the project structure, build process, and architectural decisions, particularly useful for AI-assisted development workflows.

https://claude.ai/code/session_01PjfeKeUZE8spcY4atNbymE