DACP v0.1.1 Specification: Delegation Credential Protocol for Autonomous Agent Commerce

Complete technical specification for the Delegation Credential Protocol (DACP) version 0.1.1. This document defines a JSON-LD, Ed25519-signed, version-locked, revocable credential format for autonomous agent spend delegation. Includes cryptographic hardening, replay-attack protection, audience scoping, Merkle-tree batch revocation, and extensibility framework. Defines field-by-field schema, canonical signing process, revocation model, conformance test vectors, and backward-compatibility rules.