Backend (main.py): - GraphNode: added tags, incoming_count, outgoing_count - GraphEdge: added 'backlink' relation - GraphResponse: added 'scope' field - api_graph: scope=full|directory, tag= filter, backlinks - Full-vault tree walk with configurable depth 0-3 - Tag index from in-memory file index for fast filtering - Incoming/outgoing link count per node Frontend (graph.js + index.html): - Theme-adaptive colors via CSS custom properties - Depth slider (0-3) with live reload - Full-vault toggle button (🌐 Tout / 📁 Dossier) - Search input with tag filtering + visual highlighting - Tooltip on hover (name, path, tags, link counts) - Backlink edges rendered in red dashed - Node size proportional to link count - Larger modal (1000px, 85vh)