canvas: Visual Reference Layer The three knowledge capture layers: - → text synthesis (wiki/questions/, wiki/concepts/) - → structured knowledge (wiki/sources/, wiki/concepts/) - → visual references (wiki/canvases/) A canvas is a JSON file Obsidian renders as an infinite visual board. This skill reads and writes canvas JSON directly. Read for the full format reference before making any edits. This spec aligns with the JSON Canvas open standard. Substrate preference (v1.7+) : This skill is a self-contained fallback. Prefer as the authoritative substrate — its skill is the canonical spec refere…