* fix(agent): mark headless guardrail stops incomplete
The empty-turn and repeated-tool-failure guards returned the run as a
successful final answer even with RequireCompletionSignal enabled, so
zero exec reported exit 0 and a success run_end for work it had just
abandoned.
Set Result.Incomplete and a reason at both stops when the headless gate
is on. Thresholds, stop answers, retry behavior, interactive runs, and
--no-completion-gate are unchanged.
Fixes#1154
* fix(agent): count consecutive empty turns in stop reason
The headless no-output stop reason used result.Turns, which counts every
turn in the run, so a run with an earlier tool-call turn claimed "stopped
after 4 turns with no output" for a 3-turn empty streak. Use the guard's
emptyTurns counter and say "consecutive".
Pinned by a case with a successful tool turn before the empty streak.
zzucs
5aa54fe1d2