Add a read-only MCP tool that calls Gitea's authenticated-user
endpoint (GET /api/v1/user) and returns safe identity metadata only:
username, display name, user id, email, server, and remote.
This lets future review/merge workflows prove which Gitea account the
MCP server is authenticated as, so self-review/self-merge can be
detected before acting — the blocker discovered during PR #8 dogfooding.
- Never returns the token, Authorization header, password, or secrets.
- Fails closed with a clear error if identity cannot be determined.
- No mutation; no profile switching; no review/approve/merge behavior.
Tests: identity mapping, secret-redaction, fail-closed, unknown-remote.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>