chore: Modernize CMake build, CI workflows, and code quality tooling

[monkey0722]

This pull request introduces significant improvements to the C++ project's build system, code quality tooling, and codebase consistency. The main focus is on modernizing the CMake configuration, enhancing CI workflows, enforcing code quality standards, and making minor code improvements for readability and correctness.

Build System Modernization and CI Improvements:

• Migrated to CMake 3.25+ with modern target-based configuration, introduced CMakePresets.json for standardized build and test presets, and improved compiler warning handling using target_compile_options. [1] [2] [3]
• Updated the GitHub Actions workflow to split formatting and build/test jobs, enforce clang-format checks, and use CMake presets for CI builds.

Code Quality and Tooling Enhancements:

• Refined .clang-tidy configuration to enable/disable specific checks, treat critical warnings as errors, and set header filtering for source files.
• Improved CMake targets for clang-format and clang-tidy, ensuring only source files are linted and all code is properly formatted. [1] [2]
• Added VSCode settings for YAML associations and updated documentation with requirements, build instructions, and code quality commands. [1] [2]
• Removed obsolete scripts/run_tests.sh in favor of CMake presets and CI workflows.

Codebase Consistency and Minor Fixes:

• Added [[nodiscard]] and other modern C++ attributes to key methods, improved initialization, and standardized output formatting across several data structures and algorithms. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18]

Summary of Most Important Changes:

Build System & CI Modernization

• Migrated to CMake 3.25+ with modern target-based configuration, introduced CMakePresets.json for easier builds and tests, and improved compiler warning management. [1] [2] [3]
• Updated GitHub Actions workflow to separate formatting and build/test jobs, enforce code formatting with clang-format, and use CMake presets for CI.
• Removed legacy shell script scripts/run_tests.sh in favor of CMake-based workflows.

Code Quality Tooling

• Enhanced .clang-tidy configuration: fine-tuned enabled/disabled checks, set key warnings as errors, and added header filtering for focused analysis.
• Improved CMake integration for clang-format and clang-tidy targets, ensuring correct file selection and command usage. [1] [2]
• Updated VSCode settings for better YAML support and improved documentation with requirements and code quality instructions. [1] [2]

Codebase Improvements

• Applied modern C++ best practices: added [[nodiscard]], improved initialization, standardized output, and fixed minor code issues for clarity and correctness across multiple files. [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18]