Enhance OpenClaw CLI diagnostics and upload validation

[McoreD]

This pull request introduces several documentation, configuration, and versioning updates across the project. The most significant changes include the addition of detailed contributor guidelines, a new release changelog, updated version numbers for the build system and packaging, and improvements to development blog drafts for May 10 and May 11. These updates improve contributor experience, ensure accurate release documentation, and keep project metadata consistent.

Documentation and Contributor Guidelines:

• Added a comprehensive CONTRIBUTING.md file detailing required git identity wrappers, commit format, build/test requirements, and co-author conventions for contributors.

• Added a new changelog entry in docs/CHANGELOG.md for version v0.23.27, documenting recent features, fixes, documentation updates, and changes.

Build and Packaging Updates:

• Updated project version numbers in Directory.Build.props (to 0.23.72) and build/windows/chocolatey/xerahs.nuspec (to 0.23.28), ensuring consistency across build and packaging systems. [1] [2]
• Modified the build system to import user-specific props earlier, improving local build customization.
• Updated the ShareX.ImageEditor submodule to the latest commit, pulling in upstream improvements.

Development Blog and Changelog Improvements:

• Enhanced the May 10 and May 11 development blog drafts (docs/blog/2026/2026-05/blog-20260510.md and docs/blog/2026/2026-05/blog-20260511.md) to provide more accurate summaries of features, fixes, and reviewed commits, and clarified submodule activity notes. [1] [2] [3] [4] [5]

These changes collectively improve project transparency, contributor onboarding, and release traceability.