Add AGENTS.md and CLAUDE.md for AI coding agent guidance

Author: dduugg

AGENTS.md

@@ -0,0 +1,27 @@
+# AGENTS.md
+
+This file provides guidance to AI coding agents when working with code in this repository.
+
+## What this project is
+
+A Visual Studio Code extension that integrates [packwerk](https://github.com/Shopify/packwerk) checks directly into the editor. It runs `packwerk check` (or `pks check`) on the current Ruby file and surfaces violations inline.
+
+## Commands
+
+```bash
+npm install
+
+# Compile TypeScript
+npm run vscode:prepublish   # production compile (tsc)
+
+# Watch mode during development
+npm run compile             # tsc --watch
+
+# Run tests
+npm test
+```
+
+## Architecture
+
+- `src/` — TypeScript source; extension entry point registers a command that shells out to the packwerk/pks binary and parses its output into VS Code diagnostics
+- `package.json` — declares the VS Code extension manifest, activation events, and contributed commands

CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md