Migrate to new Gitea instance (gitea.wbd-rd.nl)

- Update all submodule URLs from gitea.centraal.wbd-rd.nl to gitea.wbd-rd.nl
- Add settler as proper submodule in .gitmodules
- Add agent skills, function anchors, decisions, and improvements
- Add Docker configuration and scripts
- Add manuals and third_party docs
- Update .gitignore with secrets and build artifacts
- Remove stale .tgz build artifact

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.npmignore

@@ -1,2 +1,2 @@
-# Ignore test files
+# Ignore test files
 node_modules/