Add copilot setup workflow.

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

@@ -0,0 +1,38 @@
+name: "Copilot Setup Steps"
+
+on:
+  # Allow manual testing through the repository's "Actions" tab
+  workflow_dispatch: {}
+  # Automatically run the setup steps when an associated workflow is changed.
+  push:
+    paths:
+      - .github/workflows/copilot-setup-steps.yaml
+      - .github/actions/install-codeql/action.yaml
+      - .github/actions/install-codeql-packs/action.yaml
+  pull_request:
+    paths:
+      - .github/workflows/copilot-setup-steps.yaml
+      - .github/actions/install-codeql/action.yaml
+      - .github/actions/install-codeql-packs/action.yaml
+
+jobs:
+  # The job MUST be called `copilot-setup-steps` or it will not be picked up by Copilot.
+  copilot-setup-steps:
+    env:
+      # Primary model for detailed verification
+      PRIMARY_MODEL: "openai/gpt-4.1"
+      # Target models to verify access for - update as new models become available
+      TARGET_MODELS: "openai/gpt-4.1,openai/o1-preview,openai/o1-mini"
+    permissions:
+      contents: read
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Copilot Setup - Checkout code
+        uses: actions/checkout@v4
+
+      - name: Copilot Setup - Install CodeQL
+        uses: ./.github/actions/install-codeql
+
+      - name: Copilot Setup - Install CodeQL packs
+        uses: ./.github/actions/install-codeql-packs