OpenCode 2.2.3; external server; proxy drops only POST session interrupt.
Head after Stop timeout and after pressing Force stop:
    PID    PPID    PGID STAT COMMAND
  72843   69814   72843 Ss   /bin/bash ./build.sh
  72844   72843   72843 S    fake-gradle-worker 1800
Base at Stop:
    PID    PPID    PGID STAT COMMAND
  74389   69814   74389 Ss   /bin/bash ./build.sh
  74390   74389   74389 S    fake-gradle-worker 1800
Base 16 seconds after Stop:
    PID    PPID    PGID STAT COMMAND
  74389   69814   74389 Ss   /bin/bash ./build.sh
  74390   74389   74389 S    fake-gradle-worker 1800
Later follow-up, outside the recorded comparison: head processes still alive after Force stop; base processes no longer present:
    PID    PPID    PGID STAT COMMAND
  72843   69814   72843 Ss   /bin/bash ./build.sh
  72844   72843   72843 S    fake-gradle-worker 1800