🔧 Add AGENTS.md and copilot-setup-steps workflow (#380)

* Initial plan

* 📚 DOCS: Add AGENTS.md and copilot-setup-steps.yml workflow

Co-authored-by: chrisjsewell <2997570+chrisjsewell@users.noreply.github.com>

* 👌 IMPROVE: Add tox-uv note to AGENTS.md

Co-authored-by: chrisjsewell <2997570+chrisjsewell@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: chrisjsewell <2997570+chrisjsewell@users.noreply.github.com>

Author: Copilot

.github/workflows/copilot-setup-steps.yml

@@ -0,0 +1,36 @@
+name: Copilot Setup Steps
+
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+  pull_request:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+
+jobs:
+  copilot-setup-steps:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Python
+      uses: actions/setup-python@v5
+      with:
+        python-version: "3.11"
+        cache: pip
+
+    - name: Install uv
+      run: pip install uv
+
+    - name: Install pre-commit and pre-commit-uv
+      run: pip install pre-commit pre-commit-uv
+
+    - name: Install tox and tox-uv
+      run: pip install tox tox-uv