Decompose architecture into atomic, dependency-ordered tasks

19 tasks covering core testing, Redis hardening, WebSocket client/server
adapters, Worker adapter, and final review gates. Iroh adapters are tracked
as a deferred placeholder blocked on the @alkdev/iroh fork.

Phases: core validation → Redis hardening → review gate → WebSocket
adapters → review gate → Worker adapter → review gate → final validation.

tasks/002-core-operators-tests.md

@@ -0,0 +1,49 @@
+---
+id: core-operators-tests
+name: Write tests for all stream operators
+status: pending
+depends_on: []
+scope: moderate
+risk: low
+impact: component
+level: implementation
+---
+
+## Description
+
+The `operators.ts` module exports 13 operators (`filter`, `map`, `pipe`, `take`, `reduce`, `toArray`, `batch`, `dedupe`, `window`, `flat`, `groupBy`, `chain`, `join`). None have tests. Each operator works with `AsyncIterable` input; Repeater-returning operators (`filter`, `map`) provide backpressure-aware push semantics.
+
+The operators are adapted from graphql-yoga (`filter`, `map`, `pipe`) and added from the async-utility reference (`take`, `reduce`, `toArray`, `batch`, `dedupe`, `window`, `flat`, `groupBy`, `chain`, `join`).
+
+## Acceptance Criteria
+
+- [ ] `test/operators.test.ts` exists and passes
+- [ ] `filter` — filters items by predicate; type-narrowing overload works
+- [ ] `filter` — async predicate support
+- [ ] `map` — transforms items; async mapper support
+- [ ] `pipe` — composes 1-5 functions
+- [ ] `pipe` — compose with `subscribe`: `pipe(pubsub.subscribe("myEvent", id), filter(...), map(...))`
+- [ ] `take` — yields first N items, then stops
+- [ ] `reduce` — reduces to single value
+- [ ] `toArray` — collects all items into array
+- [ ] `batch` — groups into arrays of `size`
+- [ ] `batch` — yields remaining items if not a full batch
+- [ ] `dedupe` — yields only unique items
+- [ ] `window` — sliding window of `size` items, advancing by `step`
+- [ ] `flat` — flattens `AsyncIterable<T[]>` into `AsyncIterable<T>`
+- [ ] `groupBy` — groups items by key into `Map` (terminal operation)
+- [ ] `chain` — concatenates multiple async iterables
+- [ ] `join` — streaming join between two sources on matching keys
+
+## References
+
+- docs/architecture/api-surface.md (Operators section)
+- src/operators.ts
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion