Add repository-wide formatter checks

[bigboateng]

Summary

• add one npm run format command for JavaScript, TypeScript, JSON, Markdown, YAML, Python, Go, Rust, shell, and TOML
• use Prettier, Ruff, gofmt, rustfmt, shfmt, and Taplo with pinned third-party versions
• add a read-only formatting job to the protected validation aggregate
• format supported source files and document generated or byte-bound evaluation exclusions

The choices follow each ecosystem's standard formatter: Prettier, Ruff, gofmt, rustfmt, shfmt, and Taplo.

Validation

• npm run format:check
• go test ./...
• TypeScript, Python, and Rust SDK tests
• npm run test:release
• npm run prepare:selfhost && npm run test:selfhost
• 40/40 example workflows
• 40/40 deterministic evaluation workflows and 8/8 runtime checks
• conversion receipt validation: candidate accepted and negative control rejected
• refreshed the focused two-session gpt-5.6-sol receipt because formatting changed its byte-bound source