- relink README/CHANGELOG/pyproject/SECURITY to git.engelgardt23.ru
- update-check + badges point to Gitea; rename GITHUB_REPO -> REPO
- port CI to .gitea/workflows (self-contained, publishes Gitea release)
- remove .github (workflow + issue templates); drop made-by lines
src/netswitch.ps1 (single file, ~150 lines). CI updated to build from this
path. Added CONTRIBUTING.md describing layout, build, and release flow.
No user-visible behaviour change.