Setup build/release pipelines

[kailash-b]

✏️ Changes

Added:

• .github/actions/get-prerelease/action.yml — Composite action that checks if a version string contains beta or alpha prerelease identifiers
• .github/actions/get-release-notes/action.yml — Composite action that extracts release notes from a release/ PR body via the GitHub API
• .github/actions/get-version/action.yml — Composite action that reads the version from the .version file
• .github/actions/nuget-publish/action.yml — Composite action that packs and publishes NuGet packages to nuget.org
• .github/actions/release-create/action.yml — Composite action that creates a GitHub release with tag, body, and optional draft/prerelease flags
• .github/actions/rl-scanner/action.yml — Composite action that runs the Reversing Labs security scanner on build artifacts
• .github/actions/tag-exists/action.yml — Composite action that checks if a Git tag already exists in the repository
• .github/workflows/build.yml — Build and test workflow triggered on push/PR to master; restores, builds, runs tests with code coverage, and uploads to Codecov
• .github/workflows/nuget-release.yml — Reusable workflow that orchestrates the full NuGet + GitHub release process (version lookup, prerelease detection, release notes extraction, tag guard, NuGet publish, GitHub release creation)
• .github/workflows/release.yml — Top-level release workflow that runs RL security scanning, triggers NuGet release, generates API docs with DocFX, and deploys them to GitHub Pages
• .github/workflows/rl-secure.yml — Reusable RL-Secure workflow that builds NuGet packages, creates a tgz artifact, and runs the Reversing Labs scanner
• .github/workflows/snyk.yml — Snyk vulnerability scanning on PRs, pushes to master, and bi-monthly schedule

Removed:

• .github/workflows/ci.yml — Replaced by the new build.yml workflow
• .github/workflows/sca_scan.yml — Replaced by the new snyk.yml workflow

🔗 References

🎯 Testing

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language or why not

Workflows target .NET 10.0.x and use pinned action versions.

✅ Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors
• All commits are signed.