Add SLF4J bridge for ChromaLogger

[oss-amikos]

Summary

The ChromaLogger interface provides structured logging for transport-level events (request/response, errors). Currently only a noop() implementation exists. Users who use SLF4J (Logback, Log4j2 via SLF4J) have no out-of-the-box bridge.

Proposal

Add a Slf4jChromaLogger that implements ChromaLogger and delegates to an SLF4J Logger:

• debug(event, fields) → logger.debug("{} {}", event, fields)
• warn(event, fields) → logger.warn("{} {}", event, fields)
• error(event, fields, throwable) → logger.error("{} {}", event, fields, throwable)
• Structured fields formatted as key=value pairs or MDC entries

Usage

Client client = ChromaClient.builder()
        .baseUrl("http://localhost:8000")
        .logger(Slf4jChromaLogger.create()) // or .create("custom.logger.name")
        .build();

Considerations

• SLF4J should be an optional dependency (provided scope in Maven) — users who don't use SLF4J shouldn't pull it in
• Consider MDC (Mapped Diagnostic Context) for structured fields vs inline formatting
• Factory method pattern: Slf4jChromaLogger.create() uses default logger name, .create(String name) for custom
• Java 8 compatible

References

• ChromaLogger interface: src/main/java/tech/amikos/chromadb/v2/ChromaLogger.java
• Builder wiring: ChromaClient.Builder.logger(ChromaLogger)
• SLF4J API: https://www.slf4j.org/