feat(api): ensure StackRunConfig

StackRunConfig is part of our public API, ensure stability of this datatype using a pytest snapshot test.

If the pydantic model changes, it will fail. A snapshot can be re-generated via `@github-actions regenerate snapshots` by a code owner.

The API conformance test will then re-run and pass.

Signed-off-by: Charlie Doern <cdoern@redhat.com>

scripts/snapshot-test.sh

@@ -0,0 +1,65 @@
+#!/bin/bash
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+set -eu
+
+# Simple test runner for snapshot tests
+# Runs pytest with snapshot testing to detect schema changes
+
+# Get the script directory
+THIS_DIR=$(dirname "$0")
+ROOT_DIR="$THIS_DIR/.."
+SCRIPT=""
+REGENERATE_SNAPSHOT=""
+
+cd "$ROOT_DIR"
+
+usage() {
+    cat << EOF
+Usage: $0 [OPTIONS] <test-script> [regenerate-snapshot]
+
+Arguments:
+    test-script              Path to the test script to run (required)
+    regenerate-snapshot      Set to "true" to regenerate snapshots (optional)
+
+Options:
+    --help                   Show this help message
+
+Examples:
+    # Run snapshot test
+    $0 tests/api/test_pydantic_models.py
+
+    # Run with snapshot regeneration
+    $0 tests/api/test_pydantic_models.py true
+EOF
+    exit 0
+}
+
+# Parse command line arguments
+if [[ $# -gt 0 ]] && [[ "$1" == "--help" ]]; then
+    usage
+fi
+
+if [[ $# -lt 1 ]]; then
+    echo "Error: Missing required test script argument"
+    usage
+fi
+
+SCRIPT="$1"
+REGENERATE_SNAPSHOT="${2:-false}"
+
+# Run pytest with snapshot testing
+echo "=== Running Snapshot Tests ==="
+  if [[ "$REGENERATE_SNAPSHOT" == "true" ]]; then
+    echo "Regenerating snapshots..."
+    pytest -s -v "$SCRIPT" --snapshot-update
+    exit 0
+  else
+    pytest -s -v "$SCRIPT"  # do not update snapshots.
+  fi
+
+echo "✅ Snapshot Tests Complete"