└── util/                      # Utilities
```

### Key Design Patterns

- **Builder**: SuggesterBuilder, SuggestRequestBuilder
- **Facade**: Suggester (main entry point)
- **Composite**: NormalizerChain, ReadingConverterChain
- **Strategy**: Normalizer, ReadingConverter, ContentsParser
- **Deferred/Promise**: Async operations

### Index Alias Strategy

Zero-downtime index updates using dual aliases:

```

    // Helper methods
    // ============================================================

    protected static ReadingConverter createDefaultReadingConverter() throws IOException {
        ReadingConverterChain chain = new ReadingConverterChain();
        chain.addConverter(new KatakanaToAlphabetConverter());
        chain.init();
        return chain;
    }

    protected static Normalizer createDefaultNormalizer() {