feat: add reusable composite actions for CI workflow consolidation

Implement standardized composite actions to centralize common CI operations:

• SwiftLint validation action (.github/actions/swiftlint-validation/)
  - Standardizes code quality checks across all workflows
  - Includes optimized caching, installation, and detailed reporting
  - Supports configurable strict mode and reporter formats
  - Provides comprehensive error handling and troubleshooting guidance

• Test suite execution action (.github/actions/run-test-suite/)
  - Centralizes test execution for development, CI, and production environments
  - Supports environment-specific configuration and capability detection
  - Integrates with existing test scripts while adding standardized workflow wrapper
  - Provides rich output values for downstream workflow integration

These reusable components enable the CI consolidation effort by extracting common
patterns from existing workflows and providing standardized, well-tested interfaces
for code quality validation and test execution across all CI scenarios.

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: beriberikix