Add a graph view for visualizing relationships between documents

Feature request Please add a graph view for visualizing relationships between Outline documents, similar to the graph views in Obsidian and Logseq. Outline already supports links and backlinks between documents, but it can be difficult to understand the broader structure of a knowledge base or discover related content. An interactive graph would make these relationships easier to explore. Suggested behavior • Provide a global graph for all documents the current user can access. • Provide a local graph centered on the current document. • Represent documents as nodes and internal document links/backlinks as edges. • Allow users to click a node to open the corresponding document. • Support zooming, panning, and searching or filtering by collection. • Optionally allow controls for depth, orphan documents, and node grouping. • Respect all existing document and collection permissions so inaccessible content is never exposed. Use…