The existing `tool.result` audit event records that a tool
finished but says nothing about spillover — operators tailing
`~/.deepseek/audit.log` couldn't see when 200 KiB of stdout
landed under `~/.deepseek/tool_outputs/`.
Adds a discrete `tool.spillover` event keyed off
`apply_spillover`'s return value, fired in both the sequential
and parallel tool paths so the log entry exists regardless of
how the tool was scheduled. Each event carries:
{"event": "tool.spillover", "tool_id": "...",
"tool_name": "exec_shell", "path": "/.../call-abc.txt"}
This is a pure observability addition. The model still receives
the same truncated head + footer; the UI still renders the
inline `full output: <path>` annotation; the spillover writer
contract is unchanged. No new tests — `apply_spillover` already
has unit-level coverage and the engine paths are exercised by
integration runs.
Hunter Bown
0fa042dc99