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>

.dockerignore

@@ -0,0 +1,32 @@
+# Dependencies (rebuilt in container)
+node_modules/
+
+# Git
+.git/
+.gitmodules
+
+# Build artifacts
+*.tgz
+
+# Agent/Claude metadata (not needed at runtime)
+.agents/
+.claude/
+manuals/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Documentation (not needed at runtime)
+third_party/
+FUNCTIONAL_ISSUES_BACKLOG.md
+AGENTS.md
+README.md
+LICENSE