feat(redis): add channel prefix and error handling

tasks/001-core-pubsub-tests.md

@@ -1,7 +1,7 @@
 ---
 id: core-pubsub-tests
 name: Write tests for createPubSub, EventEnvelope, and in-process event target
-status: pending
+status: completed
 depends_on: []
 scope: moderate
 risk: low
@@ -43,8 +43,11 @@ The architecture specifies these behaviors:
 
 ## Notes
 
-> To be filled by implementation agent
+Used subscribe-based testing approach since `createPubSub` doesn't expose the internal `target`. Custom eventTarget tests use `vi.spyOn` on the provided target's `dispatchEvent` method.
 
 ## Summary
 
-> To be filled on completion
+Implemented comprehensive tests for createPubSub, EventEnvelope, and in-process event target.
+- Created: test/create_pubsub.test.ts
+- Tests: 11, all passing
+- Coverage: publish dispatches correct type:id topic, publish throws on __-prefixed types, subscribe yields EventEnvelope objects, envelope has correct type/id/payload, topic scoping (type:id matching), multiple subscribers receive events, subscriber cleanup on break, custom eventTarget dispatches to provided target, default in-process EventTarget works