Setup repo: migrate architecture specs, code stubs, and tasks from alkhub_ts

Copy architecture docs, ADRs, storage domain specs, research, reviews,
and 56 storage architecture tasks from the alkhub_ts monorepo. Adapt for
standalone @alkdev/hub repo structure (src/ not packages/hub/).

Sanitize all sensitive information:
- Replace private IPs (10.0.0.1) with localhost defaults
- Remove internal server hostnames (dev1, ns528096)
- Replace /workspace/ private paths with npm package references
- Remove hardcoded credentials from examples
- Rewrite infrastructure.md without private network details

Add Deno project scaffolding: deno.json (pinned deps), .gitignore,
AGENTS.md, entry point. Migrate existing code stubs (crypto, config
types, logger) with updated import paths.

tasks/sync/update-pubsub-doc.md

@@ -0,0 +1,45 @@
+---
+id: update-pubsub-doc
+name: Update pubsub-redis.md for @alkdev/pubsub
+status: completed
+depends_on: []
+scope: moderate
+risk: low
+impact: component
+level: implementation
+---
+
+## Description
+
+`docs/architecture/pubsub-redis.md` describes code that's now in `@alkdev/pubsub`. The doc needs a substantial rewrite to reflect the new package's API surface, including EventEnvelope, WebSocket and Worker event targets, the `prefix`/`close()` Redis API, and the expanded operator set.
+
+### Key changes
+
+1. **Source location** — Change from `packages/core/pubsub/` to `@alkdev/pubsub` npm package
+2. **createPubSub API** — Document `PubSubEventMap` pattern (simple `{ [eventType: string]: payload }`) replacing `PubSubPublishArgsByKey`. `publish(type, id, payload)` always takes 3 explicit args.
+3. **EventEnvelope** — New concept: `{ type, id, payload }` is the universal cross-process message format. Types starting with `__` are reserved for adapter control messages (used by WS event targets for `__subscribe`/`__unsubscribe`).
+4. **Redis EventTarget** — Add `prefix` option (e.g., `"alk:events:"`) and `close()` method. Remove the "configure serializer or wrap event target" workaround — `prefix` is now a parameter.
+5. **WebSocket EventTarget** — No longer "Not started" / "Deferred". Document both:
+   - `@alkdev/pubsub/event-target-websocket-client` — spoke-side adapter
+   - `@alkdev/pubsub/event-target-websocket-server` — hub-side adapter with `addConnection()`/`removeConnection()`, per-connection `SpokeEventTarget`, backpressure handling
+6. **Worker EventTarget** — New adapter: host (`createWorkerHostEventTarget(worker)`) and thread (`createWorkerThreadEventTarget()`)
+7. **Operators** — List all 13: `filter`, `map`, `pipe`, `take`, `reduce`, `toArray`, `batch`, `dedupe`, `window`, `flat`, `groupBy`, `chain`, `join`
+8. **Repeater** — Inlined, no external `@repeaterjs/repeater` dependency
+9. **Package exports** — Document the 5 subpath exports: `.`, `./event-target-redis`, `./event-target-websocket-client`, `./event-target-websocket-server`, `./event-target-worker`
+10. **Prior Art** — Update to reflect `@alkdev/pubsub` is a standalone package, not forked graphql-yoga code
+
+## Acceptance Criteria
+
+- [ ] Source location references `@alkdev/pubsub` throughout
+- [ ] `createPubSub` API docs use `PubSubEventMap` pattern
+- [ ] EventEnvelope concept is documented
+- [ ] Redis EventTarget docs include `prefix` and `close()`
+- [ ] WebSocket client and server event targets are documented (not marked as deferred)
+- [ ] Worker event target is documented
+- [ ] All 13 operators are listed
+- [ ] No references to `packages/core/pubsub/` remain
+- [ ] Prior Art section reflects standalone package, not in-repo fork
+
+## References
+
+- docs/reviews/core-library-extraction-sync-2026-05-18.md (Section 2.6)