Holds the history lock for a turn, 600 s grace period, interim texts as
core.notify. Tests with a fake LLM in the real core. The SDK tests of
/proc, /self, /run, and detached notifications now run.
Part 1 fixes: complete stdout writes, buffered stdin, Rust type names
in schemas, enum variant docs, -32603 for serde errors in handlers,
crate docs and modules. End-to-end check of a generated consumer through
a fake core.
surma