37b0b32327
- Implemented QuestionExpansionService for generating and materializing questions based on combinations and AI distillation. - Added question metadata classification logic to infer intent and layer of questions. - Created API handlers for question expansion operations including combination preview, AI distillation, metadata classification, and materialization. - Introduced database migrations to support new question-related fields and constraints in brand_questions and brand_keywords tables. - Added caching mechanism for AI distillation results to improve performance. - Defined JSON schemas for question distillation responses to ensure data integrity.