Add 'Show only files owned by you' CODEOWNERS filter

[smith]

Summary

Implements the CODEOWNERS-based file filter requested in #6624.

• Adds a toggle button (person icon) to the "Changes in Pull Request" tree view toolbar that filters files to show only those owned by the authenticated user according to the repository's CODEOWNERS file.
• New githubPullRequests.showOnlyOwnedFiles setting (default false) and pr.toggleShowOnlyOwnedFiles command.
• Composable with the existing "hide viewed files" filter.

Implementation details

• CODEOWNERS parser (src/common/codeowners.ts): Parses GitHub's CODEOWNERS format — handles anchored/unanchored paths, */** wildcards, directory patterns, ? single-char, and [...] character classes. No new dependencies; uses a custom glob-to-regex converter.
• Owner resolution: GitHubRepository.getCodeownersEntries(ref) fetches and caches the CODEOWNERS file (checks .github/CODEOWNERS, CODEOWNERS, docs/CODEOWNERS). getAuthenticatedUserTeamSlugs() fetches the user's org team memberships for @org/team pattern matching.
• Filtering: FilesCategoryNode.filterByCodeowners() applies the filter during getChildren(), matching each file's path against the parsed CODEOWNERS entries and checking ownership against the current user's login and team slugs.
• Shows "No files owned by you" placeholder when the filter yields no results.
• When no CODEOWNERS file exists, the filter is a no-op (all files shown).

Screenshot reference

The feature mirrors GitHub.com's "Only files owned by you" filter in the Files Changed tab:

Test plan

• Verify the person toggle button appears in the "Changes in Pull Request" toolbar
• Toggle on: only files matching CODEOWNERS rules for the authenticated user are shown
• Toggle off: all files are shown again
• Works with both flat and tree file layouts
• Composes correctly with "hide viewed files" (both filters active simultaneously)
• Repos without a CODEOWNERS file: filter is no-op, all files shown
• Team-based ownership (@org/team) resolves correctly when read:org scope is available
• CODEOWNERS file cached per ref — no redundant API calls on tree refresh
• All 348 existing tests pass

Closes #6624

Made with Cursor

[smith]

@microsoft-github-policy-service agree company="Elastic"

[alexr00]

@smith, I see that this is still marked as a draft. Is it ready for review, or should I wait?

[smith]

@alexr00 this should remain a draft. It's a very basic approach that probably needs more thought. If it's noisy having an open draft pr it's ok to close it.