Design separate "update translation" workflow distinct from "new translation" workflow for GDATP
GDATP currently has one workflow for all translation requests. i.e. translation workflow. We need distinct workflows for:
1. New translations, to translate entire file from scratch
2. Translation updates, to update only changed sections, but preserve existing translations
**Problem**
When users prompt for example with "translate content/es/pricing/index.yml," the agent doesn't know:
* is this a new translation (translate everything)?
* is this an update (only translate what changed in English)?
* nave Content Managers reviewed and improved previous translations?
This ambiguity leads to overwrites of human-reviewed content. See examples in issue description https://gitlab.com/gitlab-com/localization/gitlab-duo-agent-translation-platform/-/work_items/18+ . **Note** : this issue is blocked by https://gitlab.com/gitlab-com/localization/gitlab-duo-agent-translation-platform/-/work_items/18 , as we need git diff capability before we can design workflows that use it.
**How would the new 'update translation' workflow work, ideally:**
* User tells agent: "Please update \[file\] translation based on commit \[hash\]"
* Agent uses git diff analysis to identify changed sections, and only retranslates changed sections. Preserves existing translations
* Creates MR
issue