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>

.github/workflows/regenerate-snapshot-trigger.yml

@@ -0,0 +1,148 @@
+name: Run Snapshot Regeneration
+
+run-name: Run Snapshot Regeneration via PR comment
+
+
+on:
+  workflow_call:
+    inputs:
+      pr_number:
+        required: true
+        type: string
+        description: 'PR number'
+      pr_head_ref:
+        required: true
+        type: string
+        description: 'PR head branch ref'
+      pr_head_sha:
+        required: true
+        type: string
+        description: 'PR head SHA'
+      pr_head_repo:
+        required: true
+        type: string
+        description: 'PR head repository full name'
+      is_fork:
+        required: true
+        type: string
+        description: 'Whether PR is from a fork (true/false)'
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+      pull-requests: write
+
+    steps:
+      - name: Comment starting
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ inputs.pr_number }},
+              body: `⏳ Regenerating snapshots for PR #${{ inputs.pr_number }}...`
+            });
+
+      - name: Checkout PR branch (same-repo)
+        if: inputs.is_fork == 'false'
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          ref: ${{ inputs.pr_head_ref }}
+          fetch-depth: 0
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Checkout PR branch (fork)
+        if: inputs.is_fork == 'true'
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          repository: ${{ inputs.pr_head_repo }}
+          ref: ${{ inputs.pr_head_ref }}
+          fetch-depth: 0
+          token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Verify checkout
+        run: |
+          echo "Current SHA: $(git rev-parse HEAD)"
+          echo "Expected SHA: ${{ inputs.pr_head_sha }}"
+          if [[ "$(git rev-parse HEAD)" != "${{ inputs.pr_head_sha }}" ]]; then
+            echo "::error::Checked out SHA does not match expected SHA"
+            exit 1
+          fi
+
+      - name: Install dependencies
+        uses: ./.github/actions/setup-runner
+        with:
+          python-version: "3.12"
+
+      - name: Run snapshot test with regeneration
+        id: snapshot_test
+        run: |
+          uv run --no-sync ./scripts/snapshot-test.sh tests/api/test_pydantic_models.py true
+
+      - name: Check for changes
+        id: changes
+        run: |
+          if ! git diff --exit-code tests/api/snapshots/ || [ -n "$(git ls-files --others --exclude-standard tests/api/snapshots/)" ]; then
+            echo "has_changes=true" >> $GITHUB_OUTPUT
+            echo "Changes detected in snapshots"
+          else
+            echo "has_changes=false" >> $GITHUB_OUTPUT
+            echo "No snapshot changes"
+          fi
+
+      - name: Commit and push changes
+        if: steps.changes.outputs.has_changes == 'true'
+        run: |
+          git config --local user.email "github-actions[bot]@users.noreply.github.com"
+          git config --local user.name "github-actions[bot]"
+
+          git add tests/api/snapshots/
+          git commit -m "chore: regenerate snapshots for schema changes
+
+          🤖 Applied by @github-actions bot via snapshot-regenerate workflow"
+
+          # Push changes
+          git push origin HEAD:${{ inputs.pr_head_ref }}
+
+      - name: Comment success with changes
+        if: steps.changes.outputs.has_changes == 'true'
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ inputs.pr_number }},
+              body: `✅ Snapshot regeneration completed successfully!\n\n🔧 Updated snapshots have been committed and pushed to the PR branch.`
+            });
+
+      - name: Comment success without changes
+        if: steps.changes.outputs.has_changes == 'false'
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ inputs.pr_number }},
+              body: `✅ Snapshot test passed!\n\n✨ No changes needed - snapshots are already up to date.`
+            });
+
+      - name: Comment failure
+        if: failure()
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          script: |
+            await github.rest.issues.createComment({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: ${{ inputs.pr_number }},
+              body: `❌ Snapshot regeneration workflow failed!\n\nPlease check the [workflow logs](https://github.com/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}) for details.`
+            });