Add an AI assist button to the Edit/New Group (大項) and Subcategory
(小項) dialogs: the user enters a Chinese name, and the model refines
the Chinese, translates it to English, and suggests the matching IRS
Form 990 Part IX line. Suggestions surface in a confirm card; Apply
fills the Chinese name, English name, and 990 line fields.
Backend mirrors the existing expense-classification AI family but over
the Form 990 line catalog: IExpenseCategoryAiService + base (catalog
load, prompt, id validation) + Claude/Gemini providers + factory that
picks the provider from ChurchProfile.AiProvider. New write-gated
POST api/expense-categories/ai-suggest endpoint; sub-category requests
pass the parent group + its 990 line to bias the choice.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Chris Chen