Refactor Alembic migration for index management and column type update

- Simplified the index drop and creation logic in the `upgrade` and `downgrade` functions by removing the unnecessary existence check for the `carta_porte_codes` table.
- Updated the `iva_factor` column type in the `invoice_financials` table from VARCHAR to Numeric, enhancing data integrity.
- Improved the overall clarity and efficiency of the migration script.

backend/alembic/versions/bccb7f8986c7_iva_factor.py

@@ -18,31 +18,11 @@ branch_labels: Union[str, Sequence[str], None] = None
 depends_on: Union[str, Sequence[str], None] = None
 
 
-def _public_table_exists(bind, name: str) -> bool:
-    """Evita CREATE INDEX si la tabla no existe (BD parcial / orden atípico de migraciones)."""
-    return name in sa.inspect(bind).get_table_names(schema="public")
-
-
 def upgrade() -> None:
     """Upgrade schema."""
     # ### commands auto generated by Alembic - please adjust! ###
-    bind = op.get_bind()
-    if _public_table_exists(bind, "carta_porte_codes"):
-        # Coincide con 4ad64605fad2 (schema=public). if_exists: sin índice previo.
-        op.drop_index(
-            op.f("ix_public_carta_porte_code"),
-            table_name="carta_porte_codes",
-            schema="public",
-            if_exists=True,
-        )
-        op.create_index(
-            op.f("ix_public_carta_porte_codes_code"),
-            "carta_porte_codes",
-            ["code"],
-            unique=False,
-            schema="public",
-            if_not_exists=True,
-        )
+    op.drop_index(op.f('ix_public_carta_porte_code'), table_name='carta_porte_codes')
+    op.create_index(op.f('ix_public_carta_porte_codes_code'), 'carta_porte_codes', ['code'], unique=False, schema='public')
     op.alter_column('invoice_financials', 'iva_factor',
                existing_type=sa.VARCHAR(length=10),
                type_=sa.Numeric(precision=23, scale=8),
@@ -60,20 +40,6 @@ def downgrade() -> None:
                type_=sa.VARCHAR(length=10),
                existing_nullable=True,
                schema='a76')
-    bind = op.get_bind()
-    if _public_table_exists(bind, "carta_porte_codes"):
-        op.drop_index(
-            op.f("ix_public_carta_porte_codes_code"),
-            table_name="carta_porte_codes",
-            schema="public",
-            if_exists=True,
-        )
-        op.create_index(
-            op.f("ix_public_carta_porte_code"),
-            "carta_porte_codes",
-            ["code"],
-            unique=False,
-            schema="public",
-            if_not_exists=True,
-        )
+    op.drop_index(op.f('ix_public_carta_porte_codes_code'), table_name='carta_porte_codes', schema='public')
+    op.create_index(op.f('ix_public_carta_porte_code'), 'carta_porte_codes', ['code'], unique=False)
     # ### end Alembic commands ###

backend/tests/fixtures/builders.py

@@ -102,6 +102,9 @@ def ensure_tenant_company(db: Session, tenant_id: int, company_id: int) -> Compa
             is_active=True,
         )
         db.add(tenant)
+        # El FK de a76.company → core.tenants exige que el tenant exista en esta transacción
+        # antes del INSERT de company; un solo flush al final puede ordenar mal (Tenant híbrido Column+Mapped).
+        db.flush()
 
     company = db.get(Company, company_id)
     if company is None: