v0.1.0 - zkDPoP authentication framework

Initial public release for zkDPoP-Go.

zkDPoP-Go is a Go framework for zero-knowledge Demonstration of Proof-of-Possession authentication with sender-constrained JWTs.

Highlights:

• Interactive Schnorr zero-knowledge login over secp256k1 or ristretto255.
• Short-lived JWT issuance with DPoP cnf.jkt token binding.
• Per-request DPoP verification middleware for resource servers.
• Replay protection, request binding, freshness windows, and rate-limit hardening.
• Reference auth server and demo API for implementation testing.