feat(navigator): hero split layout, tree persistence, multi-language syntax, shallow retention, and docs overhaul - #34

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, actions/setup-node@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

src/components/topology/TopologyPhysicsControls.tsx:21:14: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/components/navigator/NavigatorOmniSearch.tsx:10:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/components/navigator/NavigatorOutline.tsx:30:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/components/navigator/NavigatorOutline.tsx:13:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/components/navigator/NavigatorTree.tsx:17:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/TopologyExplorer.tsx:105:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/TopologyExplorer.tsx:93:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/TopologyExplorer.tsx:29:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/components/topology/TopologyCanvas2D.tsx:23:17: Fast refresh only works when a file only exports components. Use a new file to share constants or functions between components.

src/IngestionCatalogViewer.tsx:56:64: React Hook useEffect has missing dependencies: 'fileExtension', 'pathPrefix', 'repoName', and 'loadCatalog'