README and SKILL.md: install with npx skills add, update with npx skills update; one copy per machine

README.md

@@ -2,6 +2,17 @@
 
 Agent Skill for Archify diagrams and models as read by the [Archify Diagram Viewer](https://marketplace.visualstudio.com/items?itemName=root-at-skic.archify-vscode-ext) VS Code extension: how to write `.archify` diagrams (architecture, workflow, sequence, dataflow, lifecycle), how to put them together as a model (`main.archify`, shared elements in `*.archify-registry` files, `ref:` components, `diagram:` links, C4-style folders), and tasks that validate, list, scaffold, resolve and render them. The Archify validator and renderer (MIT, by tt-a1i) are bundled under `scripts/vendor`, so nothing else needs to be installed.
 
+## Install and update
+
+One command, any agent (Claude Code, Codex, Copilot, Cline, …):
+
+```bash
+npx skills add https://gitea.lego-cloud.eu/vscode-extensions-skills/archify-vscode-ext.git --global --agent claude-code,codex,github-copilot,cline
+npx skills update --global
+```
+
+Or clone the repository into your agent's skills folder (`~/.claude/skills`, `~/.agents/skills`) and `git pull` to update. Keep one copy per machine: a skill installed twice is offered to the agent twice. The bundled Archify version is printed by every `task model:validate` run (`archify: 3.0.1`), so a stale copy is easy to spot.
+
 Quick start:
 
 ```bash

SKILL.md

@@ -28,7 +28,7 @@ Write diagrams as text next to the code, in the form the Archify Diagram Viewer
 
 Archify (MIT, by tt-a1i) is the renderer and validator. The extension bundles it; so does this skill (`scripts/vendor/archify`), so every task here runs on plain Node and needs nothing installed. The model layer (registry, `ref`, `diagram:` links) is the extension's; this skill resolves it the same way the extension does before Archify sees a diagram. Every task prints YAML on stdout (`success: true|false` first) and logs to stderr.
 
-All tasks run from this skill's `scripts/` folder:
+Install with `npx skills add https://gitea.lego-cloud.eu/vscode-extensions-skills/archify-vscode-ext.git --global`, update with `npx skills update --global`; or clone and `git pull`. One copy per machine. All tasks run from this skill's `scripts/` folder:
 
 ```bash
 cd <this-skill>/scripts