Unify CI and Release into single workflow with environment approval

Merge ci.yml, release.yml, and app-publish-artifacts.yml into a single
CI and Release workflow with 5 chained jobs:
resolve-version → build-and-test (matrix) → release-packages (approval)
→ deploy-docs → create-release.

- Add GenerateReleaseManifest NUKE target for SHA256 integrity verification
- Use GitHub environment 'release' as single approval gate
- PR runs Build+Test on ubuntu only; main push runs full platform matrix
- Release job publishes NuGet, deploys docs, creates tag and GitHub Release

Made-with: Cursor

Author: Hongwei-MB