I diagnose and fix one reproducible defect in an existing React, Vue, Node.js, or TypeScript codebase. You receive a focused patch, a regression test where practical, verification commands, and concise root-cause and handoff notes.

Please provide repository access or a source archive, exact runtime versions, reproduction steps, expected versus actual behavior, and a screenshot or sanitized log. Work is handled through written Contra messages; no call is required.

Included: one agreed defect, implementation, regression verification, and handoff notes. Excluded: new features, redesigns, major dependency migrations, paid third-party services, and handling production credentials or personal data.