Graph API

GET /api/graph/stats
Authorization: Bearer TOKEN

{
  "total_notes": 954,
  "total_links": 1081,
  "note_types": {
    "fact": 312,
    "insight": 198,
    "code_finding": 156,
    "decision": 89,
    "experience": 78,
    "synthesis": 67,
    "belief": 54
  },
  "avg_links_per_note": 2.27,
  "orphan_count": 42
}