This commit
- normalizes locales like en_GB and variants to en. With this, the feature will not translate en_GB posts to en (or similarly pt_BR to pt_PT)
- consolidates whether the feature is enabled in `DiscourseAi::Translation.enabled?`
- similarly for backfill in `DiscourseAi::Translation.backfill_enabled?`
- turns off backfill if `ai_translation_backfill_max_age_days` is 0 to keep true to what it says. Set it to a high number to backfill everything
In the earlier PR https://github.com/discourse/discourse-ai/pull/1432, when `SiteSetting.ai_translation_backfill_limit_to_public_content = false`, we **translate** PMs but **skip translating** PMs that do not involve groups.
This commit covers the missing case on **locale detection**.
Related: https://github.com/discourse/discourse-translator/pull/310
This commit includes all the jobs and event hooks to localize posts, topics, and categories.
A few notes:
- `feature_name: "translation"` because the site setting is `ai-translation` and module is `Translation`
- we will switch to proper ai-feature in the near future, and can consider using the persona_user as `localization.localizer_user_id`
- keeping things flat within the module for now as we will be moving to ai-feature soon and have to rearrange
- Settings renamed/introduced are:
- ai_translation_backfill_rate (0)
- ai_translation_backfill_limit_to_public_content (true)
- ai_translation_backfill_max_age_days (5)
- ai_translation_verbose_logs (false)
