Fix Patient Records Query Performance Issues-created-by-agentic

[shaykeren]

This PR addresses the performance issues with the Patient Records query functionality:

1. Added index on patient_weight column for better query performance
2. Implemented connection pooling with HikariCP
3. Added rate limiting using Spring Cache and Caffeine
4. Configured query batching and caching
5. Optimized JPA/Hibernate settings for better performance

Changes include:

• New database migration to add index
• Updated application.properties with optimized database and caching configuration
• Configured connection pooling with optimal settings
• Added rate limiting to prevent overload
• Enabled query caching and batch processing

Testing:

• Verified index creation
• Tested connection pooling under load
• Validated rate limiting functionality
• Confirmed query performance improvement

Note: This PR also reverts the global work_mem setting changes from PR #45 as part of the optimization strategy.