fix(ci): lint errors, remove webhook deploy, add ArgoCD GitOps k8s manifest update

- Fix ruff format: add blank line before nested function in app/views/filemanager.py
- Fix ruff format: use double-quote escaping in tests/test_config.py
- Remove deploy job (Portainer webhook) from ci.yml
- Add update-k8s-manifest job: after main-branch build, updates
  apps/docuelevate/preprod/docuelevate-stack.yaml in christianlouis/k8s-cluster-state
  with the new GHCR image tag (ghcr.io/christianlouis/docuelevate:main-<short-sha>)
  using mikefarah/yq@v4.44.6 and GH_PAT secret for cross-repo write access

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

tests/test_config.py

@@ -352,7 +352,7 @@ class TestOuterQuoteStripping:
 
     def test_mismatched_quotes_not_stripped(self):
         """Mismatched quotes (open with one type, close with another) are NOT stripped."""
-        raw = '"sqlite:///test.db\''
+        raw = "\"sqlite:///test.db'"
         config = Settings(
             database_url=raw,
             **_BASE_KWARGS,