[dashboard DDX-18d] streams per-capability dashboard section

[rickylabs]

DDX-18d / S10: Streams Console

Summary

Stream fan-out / delivery state as NetScript-primitive run-state — which subscribers received a message, delivery attempts — invisible to Aspire/Scalar. Streams is the tail of the flagship run (HTTP→workers→callback→stream fan-out).

Scope

• Delivery activity-feed; fan-out ns-step-timeline (per-subscriber delivery status/attempt); subscriber wiring pulled from the S2 graph.
• Folds any stream-side watcher/delivery events.

Non-goals

• No trace waterfall / log tail ownership (out-link to Aspire).

Acceptance criteria

• Verify contract state first: confirm a delivery/fan-out read-model exists before committing to beta.6; if absent, ship fast-follow. Lowest-shipped of the four capabilities.
• Deep-links: → S6 (streams as run tail), → Aspire trace.

Dependencies

#419, #423, #416/S2 (subscriber wiring). Wave: beta.6 if a delivery read-model exists; else wave:defer fast-follow.

Manage (P2): act: gated redeliver-to-subscriber where the delivery read-model + a redeliver route exist (same verification gate as the read-model itself; port-only = co-req flag, no invented write path); create: "New stream topic from template" via #432 (beta.7). Confirm + CLI-equivalent on every mutation.

[rickylabs]

Dependency edge (DAG second pass): Depends on #427 (DDX-17), #415 (DDX-5), #413 (DDX-3), #411 (DDX-1).