[CI] Improvements in CI and infra 24Q1

[chalin]

• Add unit/integration tests  #286
• [CI] Add smoke test via GitHub workflow #1776
• [CI] Run npm test scripts under Linux and Windows #1778
  • Cleanup: drop NPM script that is no longer needed, tweak job names #1783
• [CI] Fix markdown-link-check ignore pattern & NPM link vers update #1790
• [CI] Smoke test Docsy-based site using Hugo-modules #1794
• [CI] Disable scheduled runs of build and smoke tests #1798
• CHANGELOG copyedits & pin 0.9.0 as next release & NPM script tweaks #1809
• Use cpy-cli for OS-independent file copy #1810
  • 'npm run build' fails on Windows systems #973
  • [CI] Replace cp command by fs.copyFile + add test-all script #1806
• [CI] test:all should also check/fix format #1811
• [CI] Smoke tests failing in repo forks #1826
• Upgrade to Hugo v0.123.x #1873 etc
  • Update Hugo to 0.124.1 #1905
• Carried forward to next quarter:
  • [CI] Publish CHANGELOG and other top-level *.md files on the Docsy site and drop markdown-link-check #1781
  • [CI] Ensure smoke and npm test workflows validate successful runs #1779
  • [CI] Improvements in CI and infra 24Q1 #1780
  • [CI] For build and smoke tests, consider using actions/upload-artifact for the generated test-site files  #1799

Other & candidates:

• CI/infra CI & infrastructure
• [infra] Document official OS/env support #1782
• Add golden tests #726

Related:

• Building under Windows #1775
• [CI] Improvements in CI and infra 24Q2 #1911

[chalin]

Remaining items will be tracked via #1911.