"""`Clock` Protocol.

R-DEMO-4: production C1-C5 paths bake real-time-cadence assumptions; injected
Clock lets replay mode trip those timers consistently against tlog timestamps.

Owned by AZ-401. Bootstrap ships the interface stub.
"""

from __future__ import annotations

from datetime import datetime
from typing import Protocol


class Clock(Protocol):
    """A monotonic clock abstraction."""

    def now(self) -> datetime: ...

    def monotonic(self) -> float: ...