Handle GitHub team hierarchy in ownership reconciliation

[raiderrobert]

Problem

GitHub teams have parent/child hierarchy. If CODEOWNERS references a parent team and catalog-info.yaml references a child team (or vice versa), the tool reports "mismatched" even though the child inherits the parent's permissions.

Example:

• CODEOWNERS: @acme-corp/platform (parent)
• catalog-info.yaml: group:platform-frontend (child)
• Current result: mismatched
• Arguably correct: child inherits parent permissions

Context

In practice, when a parent team (department/org-level) is listed as owner instead of a specific child team, it often signals that nobody has claimed real ownership — it's a default that was never narrowed down. This is worth surfacing differently from a genuine parent-vs-child mismatch.

Possible approach

• Fetch team hierarchy via GitHub API (GET /orgs/{org}/teams/{team}/children)
• When comparing teams, check if one is an ancestor of the other
• Consider a distinct alignment status (e.g., HierarchyMismatch) to differentiate from unrelated team mismatches
• Potentially flag parent-team-as-owner as a smell ("owned by a department, not a team")

Complexity

Adds API calls to resolve hierarchy and complicates the reconciliation logic. Not needed for v1 where exact string matching is sufficient and broadly correct.