Background work runs as a task, not a workflow

[czpython]

A Workflow carries a run row, a subject timeline, gates, and operator-tunable settings. That weight is right for work an operator watches on a board, and wrong for plumbing — periodic maintenance, a fire-and-forget side effect. Until now the only door was Workflow, so plumbing paid the full tax.

task is the lighter door: a durable, replay-recoverable function that runs its body in one checkpointed step.

from druks.workflows import task


@task(every="*/15 * * * *")
async def refresh_tokens() -> None:
    ...


@task(retries=4)
async def sync_labels(pull_request_id: int) -> None:
    ...

• every= runs it on a fixed UTC cadence the code owns — a workflow's every= stays the one an operator can retune.
• await sync_labels.enqueue(pull_request_id=7) runs one durably in the background, from a route, a subscriber, or a workflow body.
• retries= sets retries after the first attempt; @step now takes the same knob.
• A task keeps no run row and never reaches the timeline; it has no subject, gate, or operator settings, and cannot make agent calls. That last line is the boundary — agent work stays a Workflow.

The token- and model-refresh chores move to core/tasks.py. They never belonged on the run timeline, and their cadence is no longer an operator setting. Apps declare tasks in a tasks.py capability module, discovered like workflows.py.