"""Add sequence field to product.category.

Ensures the sequence column exists with a default of 10 for all existing rows.
The ORM will also handle this on upgrade, but we add it explicitly so the
column is present before any post-install logic runs.
"""


def migrate(cr, version):
    cr.execute("""
        ALTER TABLE product_category
        ADD COLUMN IF NOT EXISTS sequence INTEGER NOT NULL DEFAULT 10;
    """)