refactor(erd): ErdViewport and ErdCanvas out of _ErdViewState, saved-view rules into the controller (#1690) - #1724

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/github-script@v7. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/