This recipe isn't idempotent

Problem/Motivation

Recipes are supposed to be idempotent, safe to apply twice or more 🤷‍♂️. That's the whole reason core actions like entity_create:createIfNotExists exist. This recipe isn't idempotent. Applying it a second time on a site that already has it fails outright.

The direct cause: setupVdbServerWithDefaults (on search_api.server.content_vector) and setupVdbIndex (on search_api.index.content_vector) both call $this->entityTypeManager->getStorage(...)->create($value)->save() unconditionally, with no check for whether the entity already exists. That code lives in the ai module, not in this recipe, so the actual fix might not be something this recipe's maintainers can make on their own.

The real question to settle first is whether idempotency is a goal for this recipe at all. If it is, that's a constraint on which actions it can use, and probably a conversation with the ai module's maintainers about adding an existence check there. If the answer is no, that's a fair call too, but it should be made on purpose, not left as a side effect of which action happened to get picked.

Steps to reproduce

1. On a fresh site: drush recipe:apply ai_recipe_content_search_vector.
2. Apply it again: drush recipe:apply ai_recipe_content_search_vector.

Second apply fails:

In SetupVdbServer.php line 116:
  Could not save the configuration.

Proposed resolution

Confirm idempotency is actually wanted here. If it is, raise an existence check with the ai module's maintainers for setupVdbServerWithDefaults and setupVdbIndex, matching what entity_create:createIfNotExists already does. Happy to submit an MR once that's agreed.

Remaining tasks

• Decide whether this recipe should be idempotent.
• If yes, coordinate with the ai module's maintainers on adding an existence check to SetupVdbServer::apply() and SetupVdbIndex::apply().