docs: add architecture diagrams (Mermaid + Archify map) for pi-dashboard

- docs/pi-dashboard.mmd — Mermaid source of truth
- docs/diagrams/pi-dashboard.png|svg — rendered via mmdc (mermaid-cli 11.16.0)
- docs/archify/pi-dashboard.architecture.json — Archify JSON IR
- docs/pi-dashboard-map.html — interactive map (9/9 showcase checks)
- docs/README.md — embedded mermaid + artifact index + regenerate commands
- visual-check screenshots/evidence at 1440x900 + 2048x1320 (light/dark)

Generated by project-diagramming-mermaid + project-diagramming-archify skills.

docs/README.md

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+# Pi Dashboard — Diagrams
+
+Architecture artifacts for pi-dashboard, generated by the `project-diagramming-mermaid` + `project-diagramming-archify` skills (per-project `docs/` convention).
+
+## Overview
+
+- **Source of truth**: [`pi-dashboard.mmd`](./pi-dashboard.mmd)
+- **Rendered** (via `mmdc`, mermaid-cli 11.16.0):
+  - [`diagrams/pi-dashboard.png`](./diagrams/pi-dashboard.png) (@2x, white bg)
+  - [`diagrams/pi-dashboard.svg`](./diagrams/pi-dashboard.svg) (vector)
+- **Interactive map** (Archify, 9/9 showcase checks): [`pi-dashboard-map.html`](./pi-dashboard-map.html) — open in a browser for pan/zoom, search, theme toggle, route tracing
+- **Archify spec** (JSON IR): [`archify/pi-dashboard.architecture.json`](./archify/pi-dashboard.architecture.json)
+
+## Diagram (Mermaid)
+
+Renders natively in Obsidian; shows as ASCII in pi via the `pi-mermaid` extension.
+
+```mermaid
+flowchart LR
+  EXT["dashboard.ts pi extension"] -->|"writes JSON"| SF[("state files ~/.pi/agent/dashboard")]
+  REM["remote machines .13 .51"] -->|"ssh cat *.json, 5s timeout + cooldown"| ST["state.go"]
+  SF -->|"readLocalStates"| ST
+  ST -->|"AgentState"| MAIN["main.go bubbletea TUI"]
+  CFG["pi-dashboard.yaml"] -->|"loadConfig"| MAIN
+  MAIN -->|"2s poll tick"| ST
+  MAIN -->|"table + detail"| UI["Table + Detail panes"]
+  UI -->|"Enter"| AT["tmux / zellij attach"]
+  UI -->|"d"| HK["hunk diff"]
+  UI -->|"Tab"| TX["tuxedo todo.txt"]
+  UI -->|"Del"| SF
+```
+
+## Regenerate
+
+```bash
+# update the source
+vim pi-dashboard.mmd
+# re-render images
+mmdc -i pi-dashboard.mmd -o diagrams/pi-dashboard.png --scale 2 -b white
+mmdc -i pi-dashboard.mmd -o diagrams/pi-dashboard.svg
+# update the Archify map (JSON IR in archify/, then):
+node ~/.agents/skills/archify/bin/archify.mjs validate architecture archify/pi-dashboard.architecture.json --quality showcase --json
+node ~/.agents/skills/archify/bin/archify.mjs deliver architecture archify/pi-dashboard.architecture.json pi-dashboard-map.html --quality showcase --json
+```