feat: Refactor template handling and brand management

- Removed schema_json from article templates and related queries.
- Updated brand service to include website field in requests and responses.
- Simplified template wizard view by eliminating unused schema fields and related logic.
- Added tests for ark text format handling.
- Created migrations for dropping schema_json and adding website to brands.

server/internal/tenant/repository/template_cache_repo.go

@@ -61,7 +61,3 @@ func (r *cachedTemplateRepository) GetTemplateByID(ctx context.Context, id, tena
 	}
 	return record, nil
 }
-
-func (r *cachedTemplateRepository) GetTemplateSchema(ctx context.Context, id int64) (*TemplateSchemaRecord, error) {
-	return r.inner.GetTemplateSchema(ctx, id)
-}