update user_id column in text_printers table to be non-nullable

opensipkd/base/alembic/versions/ab49cd111a36_initial_table_creation.py

+"""Initial table creation
+
+Revision ID: ab49cd111a36
+Revises: 975f107434c6
+Create Date: 2026-05-08 18:24:44.507154
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = 'ab49cd111a36'
+down_revision = '975f107434c6'
+branch_labels = None
+depends_on = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('text_printers', 'user_id',
+               existing_type=sa.INTEGER(),
+               nullable=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('text_printers', 'user_id',
+               existing_type=sa.INTEGER(),
+               nullable=True)
+    # ### end Alembic commands ###