fix: the backup destination migration is 0119, after the existing 0118

Two migrations both claimed revision 0118 on top of 0117, so alembic saw two
heads and the upgrade refused to run.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

alembic/versions/0119_backup_s3_destination.py

@@ -0,0 +1,43 @@
+"""import_settings: the off-site backup destination (an S3 bucket).
+
+Address, bucket, access key and region are plain settings; the secret key is
+stored sealed with the credential key. All empty means no destination is set
+up, which is every existing install's state.
+
+Revision ID: 0119
+Revises: 0118
+Create Date: 2026-11-06
+
+"""
+import sqlalchemy as sa
+from alembic import op
+
+revision = "0119"
+down_revision = "0118"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column("import_settings", sa.Column("backup_s3_endpoint", sa.Text(), nullable=True))
+    op.add_column(
+        "import_settings", sa.Column("backup_s3_bucket", sa.String(255), nullable=True),
+    )
+    op.add_column("import_settings", sa.Column("backup_s3_access_key", sa.Text(), nullable=True))
+    op.add_column(
+        "import_settings", sa.Column("backup_s3_secret_sealed", sa.Text(), nullable=True),
+    )
+    op.add_column(
+        "import_settings",
+        sa.Column(
+            "backup_s3_region", sa.String(64), nullable=False, server_default="us-east-1",
+        ),
+    )
+
+
+def downgrade() -> None:
+    for column in (
+        "backup_s3_region", "backup_s3_secret_sealed", "backup_s3_access_key",
+        "backup_s3_bucket", "backup_s3_endpoint",
+    ):
+        op.drop_column("import_settings", column)