Forward-port the six local patches onto the two new monorepo syncs
(SOURCE_REV e6a67a54 -> 84ae1223). Resolved 0001 against the runtime
full_version() injection and 0005 against the Option-wrapped
UserPromptSubmit hook payload.
Main turns now set prompt_cache_key to the session/conv id. Responses
already sent that via the conv-id fallback; Chat Completions now puts
the same value in `user`. Recap and /btw keep sharing the parent
session key — not an agent-scoped suffix.