feat: major update, focusing on unifying the CLI experience, improving docs, and modernizing the CI/CD scaffolding architecture

[Copilot]

This pull request delivers a major update to the DevOps-OS project, focusing on unifying the CLI experience, improving documentation, and modernizing the CI/CD scaffolding architecture. The highlights include a new single-source version file, a fully unified CLI (devopsos), removal of subprocess calls in favor of direct module invocation, and significant documentation improvements for onboarding and usage.

Key changes:

CLI and Codebase Improvements

• Refactored scaffold_cicd.py to directly invoke the scaffold_gha and scaffold_jenkins modules using a shared _run_module_main helper, eliminating all subprocess calls and reliance on external script files. This makes the CI/CD generator more robust and maintainable.
• Introduced cli/__version__.py as the single source of truth for the package version, and updated all version references to 0.2.0. [1] [2]
• Added a --version / -V flag to the CLI, printing the current version and exiting.

CLI Unification and Help Experience

• All scaffold subcommands (gha, jenkins, gitlab, argocd, sre, devcontainer, cicd) are now accessed via the unified devopsos CLI. Invoking any subcommand with no options prints its help text and exits cleanly, improving usability and discoverability. [1] [2] [3] [4] [5] [6]

Documentation and Onboarding

• Major improvements to README.md and README-INDEX.md:
  • Added a clear audience section, quick start command reference, and explicit CLI usage examples for every supported scaffold target.
  • Updated all usage examples and quick references to use the new unified CLI syntax (python -m cli.devopsos scaffold <target>).
  • Added links to new and updated documentation files, including a CLI test report and full command reference. [1] [2] [3] [4] [5] [6] [7] [8]

Project Metadata

• Added a CHANGELOG.md file to track all notable changes, with semantic versioning links and release notes for v0.2.0. [1] [2]

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These changes make DevOps-OS easier to use, more consistent, and simpler to maintain, especially for new contributors and users.