Factory: reconcile concurrent public metric publishers

## Outcome

Make concurrent publication of the same exact metrics record converge on one owned GitHub receipt without leaving duplicate marker comments.

## Context

Discovered during the post-remediation automated review of #307. The parent publisher already allowed two processes to observe no owned comment and both create one. #307 improves lost-response recovery but distributed GitHub mutation serialization is independent hardening.

## Acceptance criteria

- Create an OpenSpec-first bounded factory change from current `develop`.
- Define a GitHub-safe convergence protocol for concurrent publishers on different hosts.
- Preserve authenticated ownership, versioned markers, bounded retries, and local-before-remote retention.
- Reconcile or safely quarantine duplicate owned marker comments without deleting unrelated comments.
- Add deterministic race tests for two creates, lost responses, update/create overlap, and retry exhaustion.
- Keep metric payloads and remote errors privacy bounded.

## Evidence

- Source PR: #307
- Review thread: https://github.com/hyperledger-identus/sdk-rust/pull/307#discussion_r4029777949

Start from current develop and read source PR #307, including its review thread, to understand the existing publisher and lost-response handling. Define the bounded OpenSpec-first factory change, then add deterministic race tests covering the listed create, overlap, and retry cases; done means concurrent publishers converge safely without duplicate owned markers or unbounded data exposure.

Written by the indexing model from the issue text.