Ruby 3.4 Compatibility, Linting Updates, and Expanded Test Coverage

[positronicninja]

Changelog:

• Add ostruct and logger as runtime dependencies for Ruby 3.4+ stdlib compatibility
• Update minitest to ~> 5.21 for better Ruby 3.4 support
• Update standardrb to ~> 1.52 for Ruby 3.4.5 linting support
• Fix literal string mutation in Fields class to avoid Ruby 3 warnings
• Update .standard.yml ruby_version to 3.4.5
• Resolve test warnings related to deprecated stdlib gems and string handling
• Enhanced AGENTS.md with targeted testing usage examples (e.g., commands for GraphQL field generation and path configuration tests) and a comprehensive "Using the Gem" guide, drawing from test suite patterns and README documentation for better developer onboarding
• Enhanced test suite with comprehensive edge case coverage for gem usage:
  • Error handling tests for API failures and invalid configurations
  • Boundary condition tests for field generation and data handling
  • Invalid input validation for queries and attributes
  • Concurrency tests for thread-safe query loading
  • Rails integration tests for caching, routing, and localization
• Added test dependencies: webmock, mocha, concurrent-ruby for mocking and simulation
• Improved gem reliability and developer confidence through test-demonstrated usage patterns