Merge remote-tracking branch 'upstream/master' into feat/produced-files-folder

packages/host/apiproxy/README.md

@@ -36,6 +36,8 @@ Session titles ride the generic projection pair like every other domain — the
 
 Session model selection is a session-domain contract. `session.models` returns the current `ModelSelection` separately from provider-grouped advisory models, exact-model reasoning metadata, and provider-local lookup failures. The selection may be absent from the groups and is never injected as a synthetic row; clients can prompt for another selection without turning the directory into a routing whitelist. `session.selectModel` validates the optional adapter-owned reasoning effort and assigns the complete selection for the next prompt assembly. Catalog membership is not validation: an adapter may resolve an unlisted model, while an unavailable provider or unsupported effort returns `model-unavailable`. `session.models` additionally reports `routable`: whether an adapter currently serves the selected provider. This is deliberately not derivable from the groups because an adapter may serve an unadvertised model. `session.prompt` refuses on the same fact with `model-unavailable` before opening a turn; a disabled composer is a client affordance, and the method remains callable.
 
+`session.prompt` and `subagent.prompt` accept optional request-local `clientTimeZone` provenance. When present, the Host validates and canonicalizes `UTC` or an IANA Area/Location before Agent entry, rejects invalid input with `invalid-time-zone`, and records the canonical value on that exact `user-rpc` message beside its `rpcId`. The value is not Session, connection, create, resume, or fork state; non-browser callers may omit it.
+
 Pending queued input is a live control-plane contract, not conversation history. The gateway derives the complete `next-turn` queue from durable `agent/inbox/spliced` mutations and broadcasts authoritative `session/queue` snapshots after each change and on reconnect; pending `next-step` steering stays outside this Web projection. Within `next-step`, user-origin messages carry the `steering` placement while injected context (approval notices, task completion, attached snapshots) carries `context` and is not surfaced until claimed. The message-local `agent/inbox/inserted`, `claimed`, and `discarded` notifications remain available to lifecycle observers but do not build the queue view. `session.updateQueue` addresses one `MessageId`; edit and remove mutate the attached Agent through `Inbox.splice()`. A claim's pure deletion splice wins races before pre-step admission, so a later operation returns `queue-item-not-found`. `session.cancel` aborts only the active turn and preserves pending inbox work; after cancellation reaches quiescence and the closing turn flushes, AgentLoop claims the next waking message in FIFO order, and the browser never resends or promotes it. Queue operations never resume a cold session, and the client never infers retirement from turn or status events.
 
 Background tasks ride the same live-push posture. When `ctx.tasks` is composed, the gateway subscribes to its change feed and broadcasts a whole `session/tasks` snapshot after every registry commit that alters what a session can see — registration, the stopping transition, settlement, and owner-disposal removal — plus a subscription baseline for each session that already has tasks (an absent baseline is the empty set; a change that empties a set still sends `[]`). A change carrying an owner reads through that exact `Agent`, so a push stays correct while its scope tears down; the baseline reads `ctx.agents.get(sessionId)`, which yields only unowned tasks for a session with no live Agent and never resumes a cold one. An unowned change fans out to every subscribed session, because unowned tasks are visible to every caller. The wire `TaskView` drops `ownerSession`, `reported`, and `outputLimitBytes`: the frame's own `sessionId` carries the first, and the other two are internal notice and model-presentation policy. A composition without the registry emits no such frames.