v0.1.0-alpha.1

Spec-only release. Library code in src/ is
unchanged from 0.1.0-alpha.0; the bundled spec text is updated.

Spec changes

• specs/ink-auditability.md now pins the canonical
  inclusion-receipt signature format: ink/audit-inclusion/v1\n +
  JCS({eventId, leafIndex, treeSize, rootHash, timestamp}).
  Previously the spec described the signature as "over (eventId +
  treeSize + rootHash + timestamp)" without specifying a separator
  or encoding, which caused interop drift between implementations.
  No code change in this package; downstream witness and verifier
  implementations should align with the canonical format.