New EntityGraph.svelte app (sigma.js + graphology):
- Theme-aware Gruvbox palettes (light/dark) with reactive color switching
- Lucide icons rendered synchronously via Path2D canvas per entity type
- Color mode toggle (Health / Type) with per-type distinct colors
- Health distribution bar with clickable filters
- Entity type filters grouped by ontological layer (collapsible)
- Relationship type edge filters with color-coded swatches
- Quick presets: All / Problems / Infra
- Node selection with live blast radius from API
- Hover neighborhood highlighting with muted fade
- Isolated node hiding, edge alpha tuning, dot-grid background
- Search with camera focus on highest-degree match