Add standalone Cppcheck CI

[ColinLeeo]

Summary

• add a standalone Ubuntu 24.04 Cppcheck workflow for C++ changes
• pin and cache Cppcheck 2.17.1 with source archive checksum verification
• add a Maven profile that only enables CMAKE_EXPORT_COMPILE_COMMANDS
• keep existing diagnostics visible through a line-scoped baseline while failing on new diagnostics
• upload the Cppcheck report for inspection

Motivation

Cppcheck is independent of normal compilation and build artifacts. Running it in a separate CI workflow keeps the Maven build unchanged while adding cross-platform static analysis coverage for the C++ implementation.

Validation

• generated cpp/target/build/compile_commands.json through the Maven CMake goal
• ran the exact Cppcheck 2.17.1 command successfully against the latest origin/develop
• confirmed the existing baseline diagnostics remain visible and the scan exits successfully
• validated workflow YAML and cpp/pom.xml syntax
• passed git diff --check and Apache RAT checks