feat: /canvas command — visual layer of the wiki

New files:
  commands/canvas.md              — slash command with full trigger table
  skills/canvas/SKILL.md          — complete skill: open, new, add image/text/pdf/note,
                                    zone, list, from-banana operations
  skills/canvas/references/canvas-spec.md — Obsidian canvas JSON spec:
                                    coordinate system, all node types, color table,
                                    image sizing by aspect ratio, auto-positioning
                                    pseudocode, common mistakes, full example

Auto-positioning algorithm (bbox math):
  - Finds rightmost node in target zone
  - Places next node at rightmost_x + 40, same row y
  - If overflow: wraps to new row (max_y_in_zone + 20)
  - Falls back to below all content if no zone found

Banana integration:
  - /canvas from banana: checks .recent-images.txt first, then
    filesystem find -newer 10min, presents list for confirmation
  - After any /banana run: suggests /canvas from banana

Updated:
  skills/wiki/SKILL.md        — added /canvas to routing table
  skills/wiki/references/plugins.md — added Calendar + Thino with
                                      pre-installed note + manual install fallback
  README.md                   — /canvas in commands table + file structure

skills/wiki/SKILL.md

@@ -107,6 +107,7 @@ Route to the correct operation based on what the user says:
 | "lint", "health check", "clean up" | LINT | `wiki-lint` |
 | "save this", "file this", "/save" | SAVE | `save` |
 | "/autoresearch [topic]", "research [topic]" | AUTORESEARCH | `autoresearch` |
+| "/canvas", "add to canvas", "open canvas" | CANVAS | `canvas` |
 
 ---
 

skills/wiki/references/plugins.md

@@ -50,9 +50,15 @@ Install via Settings > Community Plugins > Turn off Restricted Mode > Browse.
 | **Dataview** | Query vault as a database. Powers dashboards in `wiki/meta/`. |
 | **Templater** | Auto-populate frontmatter on note creation from `_templates/`. |
 | **Obsidian Git** | Auto-commit every 15 minutes. Protects against bad writes. |
+| **Calendar** | Right-sidebar calendar with word count, task, and link indicators. Pre-installed in this vault via `.obsidian/plugins/calendar/`. |
+| **Thino** | Quick memo capture panel in right sidebar. Pre-installed via `.obsidian/plugins/thino/`. |
 | **Iconize** | Visual folder icons for navigation. |
 | **Minimal Theme** | Best dark theme for dense information display. |
 
+**Calendar and Thino are pre-installed** — they ship with this vault. Enable them in Settings → Community Plugins → toggle on. No download needed.
+
+If installing in a different vault: download `main.js` + `manifest.json` from their GitHub releases into `.obsidian/plugins/calendar/` and `.obsidian/plugins/thino/` respectively.
+
 Optional additions:
 - **Smart Connections** — semantic search across all notes
 - **QuickAdd** — macros for fast note creation