Feature coverage

Area	Mechanical evidence
Envelope, roles, targets, message kinds	contract schema tests and protocol session tests
Catalog RPC and event routing	contract catalog/routing tests; workbench handler tests
hello/welcome/ready, heartbeat, goodbye	protocol client/server and connection tests
Idempotency and retry restrictions	operation/dispatcher tests and core input/interaction deduplication tests
Dense replay/live interleaving	protocol dense-stream and subscription-recovery tests
Exact-set subscriptions and snapshots	protocol tests plus workbench recovery tests
Notify delivery and coalescing	protocol and host relay tests
Queue bounds and resync close	protocol overflow tests
Conversation replay and workbench invalidations	core storage, conversation channel and workbench connection tests
Producer and reducer lifecycle guards	contract lifecycle, workbench tool service, and UI reducer tests
HTTP/WebSocket parity	workbench dispatcher and release smoke tests
Cross-platform host semantics	shared real-host parity matrix

For a scoped change, follow AGENTS.md: review documentation diffs; for code, run focused fix/check and only the relevant unit tests. Full suites are separate CI/release validation, not a requirement for a documentation edit.