New data collection: Governance information OWNERS/CODEOWNERS parsing

Collection of information similar to: https://github.com/dpanshug/upstream-pulse/blob/main/backend/src/jobs/workers/governance-worker.ts

Start with the linked upstream-pulse governance-worker.ts as the reference for OWNERS/CODEOWNERS collection, then inspect CollectOSS's existing data-collection and relational-storage patterns. The issue does not name local files, tests, fields, or an output schema; completion would require agreeing on those details and collecting the resulting governance information.

Written by the indexing model from the issue text.