br-e2e-harness 0.3.0

[0.3.0] — 2026-06-13

Added

• br-test-harness is now feature-gated (default = ["full"]). Each heavy
  helper cluster is opt-in: nats, spawned-nats, e2e-db, server,
  passport, graphql, sse, ws, oidc; SpawnedProcess / run_once /
  wait_until stay always-compiled. A consumer can take default-features = false with a minimal feature set and drop sqlx / axum / rsa / reqwest
  / tokio-tungstenite from its build. Default consumers are unaffected (full
  = the whole toolbox). conformance-scope now takes only ["nats", "spawned-nats"], so the conformance-scope CLI binary no longer compiles the
  Postgres / Axum / JWT stacks (≈86 fewer crates in its dependency graph).

Changed

• conformance-scope derives its scope-declaration subjects from
  br-scope-declaration-contract (br-rust-common, tag v0.8.0) instead of
  hardcoding the declare / accepted / rejected subjects (and their
  event_type strings). The frozen Go wire fixture stays the independence
  anchor, so the battery now also detects subject drift: if br-rust-common
  changes a subject, the derived value diverges from the Go fixture and a
  conformance test goes red. The throwaway capture stream's identity.> wildcard
  stays a literal — it is not a contract subject.
• conformance-scope publishes accept/reject via
  br_core_integration::NatsIntegrationPublisher instead of a hand-rolled
  js.publish(serde_json::to_vec(…)) + ack — identical wire bytes, reusing the
  shared publisher instead of re-vendoring serialization.

Removed

• conformance-scope's public subject constants DECLARE_SUBJECT /
  ACCEPTED_SUBJECT / REJECTED_SUBJECT — replaced by the contract-derived
  functions declare_subject() / accepted_event_subject() /
  rejected_event_subject() (each -> Result<String, SubjectError>). A breaking
  change to the lib's symbol surface; it rides this 0.3.0 bump (a 0.x minor is
  the breaking position under Cargo semver, so consumers move by bumping the git
  tag). No in-tree consumer referenced the constants.