reaper

type Decision struct {
	Process Process
	TaskID  int // 0 when the process could not be tied to a task
	IsAgent bool
	Reap    bool
	Rule    Rule
	Reason  string
}

type KillResult struct {
	Decision Decision
	Signal   string // "TERM", "KILL", or "" when nothing was sent
	Err      error
}

type Policy struct {
	Now                  time.Time
	DoneGrace            time.Duration
	BlockedIdle          time.Duration
	OrphanMinAge         time.Duration
	ReapOrphanDevServers bool
	// Protected PIDs are never touched: the sweeping process itself and every
	// one of its ancestors. Without this, `ty sessions cleanup` run by an agent
	// from inside its own task worktree would reap the agent running it.
	Protected map[int]bool
	// OnlyTasks, when non-empty, restricts the sweep to these task IDs. Used by
	// `ty sessions suspend`, which should only clean up after what it suspended.
	OnlyTasks map[int]bool
	// Explicit marks a teardown the user asked for by name rather than one
	// inferred from staleness. Status-based caution (the active-task guard, the
	// idle thresholds, sparing the agent) exists to avoid guessing wrong about
	// abandoned work; when someone runs `ty sessions suspend 42` there is no
	// guessing left to do. Only meaningful together with OnlyTasks.
	Explicit bool
}

type Process struct {
	PID     int
	PPID    int
	TTY     string        // "?" / "??" when the process has no controlling terminal
	Age     time.Duration // elapsed time since the process started
	Command string        // full command line
}

type Rule string

type Signaller func(pid int, sig syscall.Signal) error

type TaskState struct {
	Exists bool
	Status string
	// LastActivity is the most recent sign of life for the task: status
	// changes, log lines, the UI opening it. Staleness is measured from here
	// and NOT from when the task entered its current status, so a task that is
	// blocked but actively being poked at is never considered abandoned.
	LastActivity time.Time
	// WorktreeDir is the basename of the task's recorded worktree
	// ("5119-creator-referral-v2"), or "" if none is recorded. A process whose
	// worktree directory differs belongs to some other task that happens to
	// share the ID — typically one placed here from another machine.
	WorktreeDir string
}