Rename the import package app to fluksio

A wheel whose top-level module is `app` collides with anything else in a
user's venv, so the package that is about to be published takes the name
it is published under. Only the Python package moves; the repo, the
Docker WORKDIR and the compose project keep theirs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

backend/fluksio/alembic/versions/1a31ce608336_add_cascade_delete_relationships.py

@@ -0,0 +1,37 @@
+"""Add cascade delete relationships
+
+Revision ID: 1a31ce608336
+Revises: d98dd8ec85a3
+Create Date: 2024-07-31 22:24:34.447891
+
+"""
+from alembic import op
+import sqlalchemy as sa
+import sqlmodel.sql.sqltypes
+
+
+# revision identifiers, used by Alembic.
+revision = '1a31ce608336'
+down_revision = 'd98dd8ec85a3'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column('item', 'owner_id',
+               existing_type=sa.UUID(),
+               nullable=False)
+    op.drop_constraint('item_owner_id_fkey', 'item', type_='foreignkey')
+    op.create_foreign_key(None, 'item', 'user', ['owner_id'], ['id'], ondelete='CASCADE')
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_constraint(None, 'item', type_='foreignkey')
+    op.create_foreign_key('item_owner_id_fkey', 'item', 'user', ['owner_id'], ['id'])
+    op.alter_column('item', 'owner_id',
+               existing_type=sa.UUID(),
+               nullable=True)
+    # ### end Alembic commands ###