v0.3.0 - Thread-safety, connection pooling, and SSL improvements

Added

• Thread-safe metrics with Mutex protection for concurrent usage
• Connection pooling with net-http-persistent (automatic connection reuse)
• SSL/TLS configuration options: ssl_verify_mode, ssl_ca_file, ssl_ca_path, ssl_timeout
• Thread-safe logger cache for warn_once method
• Comprehensive concurrent/async documentation with SolidQueue, Sidekiq, Concurrent Ruby examples
• 39 new tests for thread-safety, SSL configuration, and connection pooling

Changed

• HTTP client now uses Net::HTTP::Persistent for better performance
• Configuration metrics now thread-safe across concurrent requests
• Documentation reorganized with SolidQueue as recommended background job backend

Performance

• Connection pooling reduces TCP handshake overhead
• Thread-safe implementation enables safe concurrent translations
• Configurable SSL timeout for production environments

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Full Changelog: https://github.com/Peyochanchan/mistral_translator/blob/main/CHANGELOG.md

All tests passing: 442 examples, 0 failures