Cleanup/lambda fhir processor

[lab596]

This pull request introduces extensive documentation, development utilities, and configuration files to the fhir-processor Lambda project. The main focus is on providing a comprehensive technical overview, supporting local development and testing, and ensuring correct dependency management and AWS permissions. No core processing code is changed, but these additions significantly improve maintainability, onboarding, and troubleshooting.

Documentation and Developer Support:

• Added a detailed README.md explaining architecture, differential update logic, FHIR resource mapping, data flow, environment variables, testing strategies, error handling, and future enhancements. This serves as a technical reference for developers and stakeholders.
• Added several utility scripts for local inspection and testing:
  • inspect_dump.py, inspect_counts.py, inspect_encrypted_dump.py for analyzing SQL dumps and encrypted files.
  • inspect_keys.py for extracting key usage from the processing code.
  • local_parse_test.py for locally testing the SQL parser. [1] [2] [3] [4] [5]

Configuration and Dependency Management:

• Added requirements.txt and requirements-dev.txt specifying all runtime and development dependencies, including FHIR libraries, database drivers, AWS SDK, and encryption utilities. [1] [2]
• Added .gitignore to exclude Python caches, test artifacts, and logs from version control.

AWS Integration and Permissions:

• Added sample S3 event (invoke_event.json) and Lambda response/error files (invoke_result.json, response.json) to aid in local simulation and debugging. [1] [2] [3]
• Added an S3 read policy JSON (s3-read-policy.json) granting the Lambda function necessary permissions to read from the S3 bucket.