- Rename 'personalization' field to 'personalize' in API
- Rename 'userProfile' to 'userContext' in personalization object
- Remove 'personalized' boolean field (activation now based on non-null 'personalize')
- Move personalization checks inside rerank_search_results function
- Use 'let else' pattern for better error handling
- Update error types and messages to reflect new field names
- Update all search routes and analytics to use new field names
- Add Personalization struct with personalized boolean and user_profile string
- Add personalizationPersonalized and personalizationUserProfile query parameters to SearchQueryGet
- Follow same pattern as hybrid parameters (hybridEmbedder, hybridSemanticRatio)
- Add validation: personalizationUserProfile requires personalizationPersonalized
- Add error codes for personalization parameters
- Update analytics and facet search to handle new personalization field
- Remove serde dependencies from Personalization struct, use Deserr only
- Add MEILI_EXPERIMENTAL_PERSONALIZATION_API_KEY environment variable
- Add experimental_personalization_api_key field to Opt struct with CLI and env support
- Add experimental_personalization_api_key field to InstanceTogglableFeatures
- Store personalization API key in FeatureData for access through IndexScheduler
- Add experimental_personalization_api_key() method to IndexScheduler
- Update analytics destructuring to include new field
- Maintain RoFeatures Copy trait while properly handling Option<String>
