First public release of aetherproof-verify.

Features:
- Offline Ed25519 signature verification for AetherProof v1 manifests
- RFC 8785 JCS canonicalization
- Pydantic v2 schema with extra='forbid' + frozen=True
- CLI: aetherproof-verify check --manifest X --pubkey Y [--fingerprint Z]
- Python 3.10-3.13 support

Supply-chain posture:
- Built via GitHub Actions with PEP 740 attestations (Sigstore)
- Published via PyPI Trusted Publisher (OIDC, no API tokens)
- Deps: cryptography>=46.0.7 (CVE-clean), pydantic>=2.13, jcs==0.2.1

Schema parity hash: fd1bcc4080a44d7147068612008a4fb3a0a2b03f9dd32a233fde3a8ae93537a4