feat(server,watch): threads remember the dispatch origin header and report it back

README.md

@@ -21,7 +21,7 @@ Built for the dispatcher in [beaver-agent](https://git.kotikot.com/beaver/beaver
 
 ## Events
 
-The connector keeps a websocket subscription to every machine (`orchestration.subscribeShell`, Effect RPC over JSON, reconnect with replay). Threads started through `t3_dispatch` are tracked in a state file; the transitions running → completed / interrupted / failed and a new pending question become events, `POST`ed to `T3CODE_MCP_HOOK_URL` with a bearer through a persisted outbox with retries. In the beaver setup that URL is the gateway's `/hooks/t3code`, and the event lands in the master conversation as an urgent inject. Every `t3_dispatch` subscribes its thread, a continuation included; `t3_watch(thread_id, enabled=false)` or `t3_dispatch(..., watch=false)` lets a thread run silently.
+The connector keeps a websocket subscription to every machine (`orchestration.subscribeShell`, Effect RPC over JSON, reconnect with replay). Threads started through `t3_dispatch` are tracked in a state file; the transitions running → completed / interrupted / failed and a new pending question become events, `POST`ed to `T3CODE_MCP_HOOK_URL` with a bearer through a persisted outbox with retries. In the beaver setup that URL is the gateway's `/hooks/t3code`. `t3_dispatch` remembers the `X-Conversation-Origin` request header as the thread's `origin` and every event carries it back; the beaver gateway puts the calling conversation's id there, so the event lands as an urgent inject in the conversation that started the thread (the master when it is gone or the header was absent). Every `t3_dispatch` subscribes its thread, a continuation included; `t3_watch(thread_id, enabled=false)` or `t3_dispatch(..., watch=false)` lets a thread run silently.
 
 ## Configuration