v0.1.0 — Phase 1 stable

Phase 1 stable. Real-network smoke gate is green.

Added

• scripts/smoke/real/ — 9-step end-to-end suite that exercises the
  gateway against a live cosmos-pay facilitator on Cosmos testnet
  grand-1. Each 05-settle.sh run broadcasts a real
  MsgExec(MsgSend) and asserts the on-chain txHash round-trips
  through /settle and /payments/:id.
• Fixture generator at x402-cosmos/tools/fixture/ produces a fresh
  ADR-036-signed PaymentPayload + matching PaymentRequirements
  per invocation. Cross-repo, referenced over HTTP; no vendored Go
  code lands in this TypeScript monorepo.

Verified

• Idempotency invariant under real on-chain conditions: a duplicate
  /settle with the same Idempotency-Key returns the same
  paymentId and the same on-chain txHash, and /payments/:id
  reports exactly one attempt (no second broadcast).
• cosmos-pay HTTP integration via real /verify and /settle.
  /providers reports cosmos-pay healthy when the facilitator is
  reachable, and runtime capability discovery correctly supersedes
  the adapter's static mainnet capability with the testnet one
  the facilitator actually offers.

Deferred to v0.2+

• Coinbase CDP real-network smoke (requires CDP API key).
• Cross-provider fallback under real conditions (requires a second
  reachable facilitator).
• Race-replay terminal state polish (see "Known limitations" in
  README — duplicate /settle may transiently surface as pending).
• SIGHUP-style admin api_key rotation without server restart.