v0.3.0

Minor Changes

• a6a0293: Ship chain verification in all five languages, and prove it with corrupted-chain
  corpus vectors.

  verifyChain — the function that actually DETECTS a broken hash chain — existed
  only in TypeScript. Python carried a docstring describing how one would verify;
  Rust, Go, and .NET had nothing. A service in four of five languages could seal a
  chain it could never audit, which makes "tamper-evident" a claim rather than a
  capability.

  • New: verify_chain (Python, Rust), VerifyChain (Go), HashChain.Verify
    (.NET). All five return the same verdict shape: ok, brokenAt, and a shared
    failure code — hash_previous_mismatch (the link is wrong) or
    hash_current_mismatch (the event body was edited after sealing).
  • verifyChain gains an optional genesisPreviousHash, so a slice continuing an
    existing chain can be verified at all. Without it, only a first-of-day chain
    was verifiable. TypeScript additionally gains a code field alongside the
    existing human-readable reason (additive; reason is unchanged).
  • spec/parity-corpus.json gains chainFixtures: 11 real chains, sealed by the
    builder and then genuinely tampered with, each with the verdict every language
    must return. All five suites load them. The corpus previously proved sealing
    only, which is what let the asymmetry hide.
  • One fixture asserts the honest limit: deleting events from the TAIL of a chain
    still verifies. Replay cannot see it; catching it needs an external anchor.