Plugin baselines skip tables that already exist

plugins/printedparts/migrations/versions/0002_printeditemfiles.py

@@ -5,6 +5,11 @@ the ADR-008 payoff: the plugin evolves its own schema without touching
 the core chain. Applied by `flask plugin upgrade-all`.
 """
 from alembic import op
+
+from shopdb.plugins.alembic_template import (
+    create_index_if_missing,
+    create_table_if_missing,
+)
 import sqlalchemy as sa
 
 
@@ -16,7 +21,7 @@ depends_on = None
 
 
 def upgrade():
-    op.create_table(
+    create_table_if_missing(
         'printeditemfiles',
         sa.Column('fileid', sa.Integer(), nullable=False),
         sa.Column('printeditemid', sa.Integer(), nullable=False),
@@ -35,8 +40,8 @@ def upgrade():
         sa.PrimaryKeyConstraint('fileid'),
         sa.UniqueConstraint('storedfilename'),
     )
-    op.create_index('ix_printeditemfiles_printeditemid',
-                    'printeditemfiles', ['printeditemid'])
+    create_index_if_missing('ix_printeditemfiles_printeditemid',
+                            'printeditemfiles', ['printeditemid'])
 
 
 def downgrade():