Fix linter problems and enforce linter on pipeline

Right now the linter is just raising warnings. Fix those and then enforce the linter in the pipeline.

Inspect the repository's linter configuration and pipeline definition, then run the linter to identify the current warnings. Fix the reported linter problems and update the pipeline so lint failures stop it; done means the linter passes cleanly and is enforced in the pipeline.

Written by the indexing model from the issue text.