When a tool call itself restarts the gateway (docker restart, systemctl
restart, and similar), the process is terminated mid-call — before the
tool result is persisted and before the orderly drain rewind can run. The
transcript tail is left as an assistant(tool_calls) with no matching tool
answer. On resume the model re-issues the unanswered call, taking the
gateway down again — an infinite loop (#49201).
Source fix: _build_gateway_agent_history now strips a trailing
assistant(tool_calls) block that has no tool answers
(_strip_dangling_tool_call_tail), so there is nothing for the model to
re-execute. This complements _strip_interrupted_tool_tails, which only
handles the case where a tool result row exists with an interrupt marker.
Cognitive backstop: the resume-pending system note now states that any
restart command in the history already ran and must not be re-executed or
verified, and the empty-message auto-resume startup turn reports recovery
and asks for instructions instead of the nonsensical "address the user's
NEW message" (there is no new message on that turn).
Reimplements the intent of #49243 by @JoaoMarcos44 at the replay layer.
Fixes#49201