Plugin baselines skip tables that already exist

plugins/backups/migrations/versions/0001_backups_baseline.py

@@ -12,6 +12,11 @@ time (NoReferencedTableError). Same shape autogenerate produces. Tables inherit
 the connection's default charset, matching how the core chain creates its own.
 """
 from alembic import op
+
+from shopdb.plugins.alembic_template import (
+    create_index_if_missing,
+    create_table_if_missing,
+)
 import sqlalchemy as sa
 
 
@@ -23,7 +28,7 @@ depends_on = None
 
 
 def upgrade():
-    op.create_table(
+    create_table_if_missing(
         'backuprevisions',
         sa.Column('backuprevisionid', sa.Integer(), nullable=False),
         sa.Column('assetid', sa.Integer(), nullable=False),
@@ -42,15 +47,15 @@ def upgrade():
                                 ondelete='CASCADE'),
         sa.PrimaryKeyConstraint('backuprevisionid'),
     )
-    op.create_index('ixbackuprevisionsassetid', 'backuprevisions', ['assetid'])
-    op.create_index('ixbackuprevisionsbackupkind', 'backuprevisions',
-                    ['backupkind'])
-    op.create_index('ixbackuprevisionscontenthash', 'backuprevisions',
-                    ['contenthash'])
+    create_index_if_missing('ixbackuprevisionsassetid', 'backuprevisions', ['assetid'])
+    create_index_if_missing('ixbackuprevisionsbackupkind', 'backuprevisions',
+                            ['backupkind'])
+    create_index_if_missing('ixbackuprevisionscontenthash', 'backuprevisions',
+                            ['contenthash'])
     # The dedup read path is "latest revision for this asset+kind", so the
     # composite index is the one that actually gets used on every collector post.
-    op.create_index('ixbackuprevisionsassetkind', 'backuprevisions',
-                    ['assetid', 'backupkind'])
+    create_index_if_missing('ixbackuprevisionsassetkind', 'backuprevisions',
+                            ['assetid', 'backupkind'])
 
 
 def downgrade():