Identity-Attributed Git Commits via Tier-Structured Trailers

This document defines a git commit trailer grammar for identity- attributed contributions using the ~handle identity primitive defined in [MCPDNS]. The grammar binds sovereign actors, automated bots, and AI instruments to specific commits via three tier-structured trailers (Acted-By, Executed-By, Drafted-With) and three optional cryptographic trailers (Identity-Signature, Identity-Key-Id, Identity-Anchor). The signature is computed with Ed25519 over the commit's tree hash rather than its commit hash, preserving attribution across rebase, cherry-pick, and squash merge operations. Conformant parsers reject cross-tier category errors (e.g., an Instrument-tier handle in an Acted-By slot) as malformed. The mechanism is provider-neutral, depends only on DNS [RFC1035] and the ~handle resolution algorithm of [MCPDNS], and requires no central authority or platform-specific verification service.