"""external_link.started_at: when a fetch claimed the link.

A worker killed mid-fetch (the Celery hard limit, an OOM, a restart) never
reaches the code that moves its link out of 'downloading'. The external-link
sweep returns such a link to the retry path once it has been 'downloading'
longer than the task's hard limit, which needs the claim time.

A row in 'downloading' with no claim time is treated as stale: no worker
survives the deploy that adds this column.

Revision ID: 0117
Revises: 0116
Create Date: 2026-11-05

"""
import sqlalchemy as sa
from alembic import op

revision = "0117"
down_revision = "0116"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column(
        "external_link",
        sa.Column("started_at", sa.DateTime(timezone=True), nullable=True),
    )


def downgrade() -> None:
    op.drop_column("external_link", "started_at")