- Add new personalization module with Cohere integration
- Implement rerank_search_results method using EnglishV3 model
- Remove fallback logic to EnglishV2 for simplified behavior
- Add comprehensive error handling and logging
- Include unit tests for service behavior
- Update search route to support personalization feature
- 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>
