End-to-end mutual TLS without a reverse proxy. Go binary terminates
TLS itself via ListenAndServeTLS. TLS_MODE config (none/server/mtls)
is independent of AUTH_MODE.
- MTLSNativeProvider reads PeerCertificates directly (no header trust)
- Shared helpers extracted to mtls_helpers.go (ParseDN, FingerprintCert)
- MTLSProvider renamed to MTLSProxyProvider for clarity
- BuildPeerTLSConfig for future node-to-node mTLS
- switchboard-ca.sh: CA init, issue-node, issue-user (ECDSA P-256)
- 12 new tests (unit + TLS integration)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
