feat(db): add PostgreSQL/SQLite async DB layer with SQLAlchemy 2.0

feat: add diabetes model artifacts, training pipelines, and feature engineering

chore: move heart11.csv to raw/ + update .gitignore + add transform_heart11.py & vercel.json

fix: add missing engineer_medical method to HeartDiseaseFeatureEngineer + update preprocessors

fix: resolve model path and finalize project restructuring

chore: remove binary files rejected by Hugging Face Spaces

Duplicate raw, processed, and interim data files into the new data/heart_disease/ directory structure to support the multi-disease platform refactor. Original files remain untouched.

Refactor code structure for improved readability and maintainability

Add label encoders and standard scaler as binary files for preprocessing

Implement code changes to enhance functionality and improve performance

feat: setup V3 architecture and add data harmonization pipeline

Refactor project structure to standard Data Science architecture

Refactor code structure for improved readability and maintainability

Update heart.csv

Merge remote skeleton into local project