feat: #3585563 Record AI translations in AI Disclosure

Description

Issue #3585563 (closed).

Each AI translation gets the "AI translated" grade of AI Disclosure: entities, referenced entities and Layout Builder blocks. A new translation does not inherit the human review of its source: the copied field is emptied, the source's grade is applied, then "AI translated", and the stricter stays. A recording failure is logged and never stops the save. Existing sites keep the setting off after drush updb. 2.0.x needs a port.

Testing instructions

1. Install AI Disclosure and add its field, translatable, to Article.
2. Turn on "Record AI translations in AI Disclosure" and translate an article from the Translate tab: the translation has "AI translated", the source keeps its value.

Checklist

• I have linked the related issue in the MR title or description
• I have performed a self-review of my own code
• I have added or updated tests, or explained in the description why this change is not covered by tests
• I have updated documentation for any new or changed functionality
• I have written testing instructions and verified them locally
• I have noted any required post-merge steps (config imports, cache rebuilds, manual changes): drush updb runs ai_translate_update_10005, existing sites opt in
• This MR contains no breaking API or hook changes, or they are explicitly documented in the description: optional trailing arguments only

AI Compliance

🤖 Generated with the help of an LLM, reviewed and approved by me.