test/docs(shared-queues): journey + docs (D3.3)

CLI journey (shared_queues): authoring + `pic triggers ls --group` shared
column + the two validation rejections (undeclared queue collection; shared
on an app), mirroring the shared_topics/shared_triggers norm; the live
competing-consumer + dispatcher behaviour is pinned by the deterministic
manager-core tests. Docs: CLAUDE.md + design doc §11.6 record D3 as shipped.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/design/groups-and-project-tool.md

@@ -1205,8 +1205,18 @@ Resolved items now live inline next to their topic. What genuinely remains:
    > (group-only) — the `shared` flag + owning-group chain walk are the isolation boundary. No message store
    > (topics are events, not persistence). Pinned by `tests/shared_topics.rs` + the `shared_topics` journey.
    >
-   > **Deferred (documented gaps):** shared-topic external SSE subscription; **queue** shared collections
-   > (D3, competing per-descendant consumers over a group-keyed store); per-group total-size quotas +
+   > **Shipped — D3 shared durable QUEUES (competing consumers).** A group declares a `queue` shared
+   > collection; any subtree app enqueues into ONE group-keyed store (`group_queue_messages`, `0065`) via
+   > `queue::shared_collection("name").enqueue(...)` (editor+, `GroupQueueEnqueue`). A group
+   > `[[triggers.queue]] shared = true` consumer **materializes** a consumer copy per descendant app (the
+   > M5 one-consumer-slot check is skipped for shared), and all copies claim the shared store with `FOR
+   > UPDATE SKIP LOCKED` — at-most-once across the subtree, horizontally scaled, each handler under its own
+   > `cx.app_id`. The dispatcher's queue arm routes claim/ack/nack/terminal to the group store when the
+   > consumer's source template is a shared queue (`ActiveQueueConsumer.shared_group`). Pinned by
+   > `tests/group_queue.rs` + `stateful_templates.rs` + the `shared_queues` journey. **Deferred:** a group
+   > dead-letter store (an exhausted shared-queue message is dropped-with-warning).
+   >
+   > **Deferred (documented gaps):** shared-topic external SSE subscription; per-group total-size quotas +
    > write-rate limits;
    > CAS/`set_if`; an operator admin API for shared blobs (scripts use the SDK; `pic collections ls` shows
    > the marker — matches KV/docs); app-declared collections. Multi-node tree-apply leans on the runtime