Bundle native runtime libraries and notices

[QiuYe-123]

Description

Bundle redistributable native runtime dependencies for non-Android platforms and stage the corresponding notices alongside the packaged libraries.

This change addresses the gap found in the latest pre-release jar, where:

• Windows x86-64 was self-contained, but Linux and macOS still shipped only the primary bigmath_ffm library
• Windows ARM64 still depended on Microsoft VC++ runtime DLLs that were not bundled
• third-party license texts and runtime notices were documented centrally, but were not staged next to each classifier payload

Changes in this PR:

• add a Unix staging script that copies bundled GMP/MPFR runtime libraries into native/<classifier>/
• rewrite macOS runtime references to @loader_path so bundled GMP/MPFR libraries are used after extraction
• add a Windows staging script that preserves MinGW runtime DLL packaging and stages Microsoft VC++ runtime DLLs for ARM64 builds when present
• stage a per-classifier licenses/ directory alongside bundled native libraries
• update snapshot, release, and PR native workflows to use the new staging scripts before uploading artifacts
• expand THIRD_PARTY_NOTICES.md to document Microsoft VC++ runtime redistribution and classifier-local notice staging

Type of Change

• New feature (type: feature)
• Bug fix (type: bugfix)
• Build/CI (type: build)
• Refactoring (type: refactor)
• Documentation (type: docs)
• Tests (type: tests)

Native Changes

• This PR changes native C++ code (requires ci:native label for full platform testing)
• No native C++ source changes, but native packaging/workflows are affected

Testing

Local validation focused on workflow and staging script correctness.

./gradlew.bat spotlessCheck -x buildNative -x cmakeConfigure
git diff --check
bash -n .github/scripts/stage-native-runtime-unix.sh
powershell parse check for .github/scripts/stage-native-runtime-windows.ps1

Verified locally:

• spotlessCheck passes after the workflow and notice changes
• shell and PowerShell staging scripts parse successfully
• the new logic keeps Android unchanged while preparing non-Android runtime staging
• unpack inspection of the latest pre-release jar confirms the packaging gaps this change is targeting

Checklist

• My code follows the project's code style
• I have added tests that prove my fix/feature works
• ./gradlew spotlessCheck passes