ChatCrystal v0.5.0

Knowledge Graph

• Tag knowledge graph - Rebuilt the default graph experience around tags as knowledge-point nodes, with normalized co-occurrence edges so the graph remains useful without explicit note-relation analysis.
• Scalable graph projection - Added /api/graph/projection as a bounded render-ready graph API, while keeping the legacy note relation graph API for compatibility.
• Sigma graph engine - Migrated the graph canvas from react-force-graph-2d to Sigma.js and Graphology for a stronger foundation as note collections grow.
• Knowledge-point details - Clicking a tag now opens a right-side detail panel with related notes, project metadata, and direct note navigation.
• Graph readability polish - Refined light/dark theme contrast, label rendering, hover cards, zoom controls, neighborhood highlighting, and lower-left graph controls for a clearer workspace.

Documentation

• Updated README screenshots, user guides, and development docs to describe the tag-based knowledge graph and the graph projection API.