fix: update CODEOWNERS — replace upstream fork handles with Safrochain maintainers

[Karry2019web]

Summary

Closes #36

The current .github/CODEOWNERS contains handles (@JakeHartnell, @dimiandre, @niilptr, @vexxvakan) that belong to individuals outside the Safrochain-Org organization — a leftover from the upstream fork. This means every PR auto-requests reviews from people who are not Safrochain maintainers, which is noisy for them and means no auto-request goes to the actual team.

Changes

• Replaced stale external handles with @danbaruka and @elielnfinic (current maintainers/contributors)
• Added granular directory-level rules for x/ custom modules, /app, /.github, /docs, Makefile, Dockerfile, goreleaser.yml, etc.
• Retained the wildcard * default rule as fallback

Why this layout

• Fine-grained paths ensure the right people are pinged for the right code areas
• The wildcard default catches anything not explicitly listed
• No GitHub teams are defined in Safrochain-Org yet (only @danbaruka is an org member); individual handles are used until teams are created

Acceptance criteria

• No GitHub handles outside the Safrochain-Org org remain in CODEOWNERS
• PR review requests route to Safrochain maintainers
• Granular rules exist for custom modules, CI, and docs

Related

• Fixes chore: update .github/CODEOWNERS — current entries point to non-Safrochain handles #36