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/004-redis-channel-prefix-and-error-handling.md

@@ -0,0 +1,45 @@
+---
+id: redis-channel-prefix-and-error-handling
+name: Add channel prefix and error handling to Redis event target
+status: pending
+depends_on: [redis-adapter-tests]
+scope: narrow
+risk: low
+impact: component
+level: implementation
+---
+
+## Description
+
+The architecture doc for the Redis adapter lists two limitations that need to be addressed:
+
+1. **No channel prefix** — raw event types as channel names risk collision in shared Redis instances. The adapter should support a configurable prefix like `createRedisEventTarget({ ..., prefix: "alk:events:" })`.
+
+2. **No error handling** — connection failures, reconnection, and message parse errors are not handled. The adapter should:
+   - Handle serializer parse errors gracefully (log warning, skip message)
+   - Handle subscribe client disconnect gracefully (registered callbacks remain but won't fire)
+   - Note that in-flight messages after unsubscribe are harmless (empty callback set = no-op)
+
+These are quality-of-life improvements that make the adapter production-ready.
+
+## Acceptance Criteria
+
+- [ ] `CreateRedisEventTargetArgs` accepts an optional `prefix` field (string, default `""`)
+- [ ] When `prefix` is set, channel names are prefixed: `"alk:events:call.responded:uuid-123"`
+- [ ] Both publish and subscribe use the same prefix convention
+- [ ] Malformed messages from Redis (serializer parse errors) are caught and logged, not thrown
+- [ ] Existing tests updated to cover prefix behavior
+- [ ] New tests for prefix behavior and error handling
+
+## References
+
+- docs/architecture/event-targets/redis.md (Limitations section)
+- src/event-target-redis.ts
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion