60db provides a hosted text-to-speech API using workspace voices. This change adds an optional sixtydb driver to the existing manager.
Set SIXTYDB_API_KEY and SIXTYDB_VOICE_ID, then call TextToSpeech::engine('sixtydb')->saveTo('speech.wav')->convert('Hello').
The driver reuses source, disk, path, and language APIs and the existing Guzzle dependency. It accepts supported binary and JSON/NDJSON audio envelopes and saves mono PCM16 WAV at 24 kHz. Inputs, metadata, and response sizes are validated; redirects are disabled and HTTP, decoding, and storage failures are surfaced. Configuration and usage documentation are included.
Validation: 8 focused PHPUnit tests with 32 assertions passed using Guzzle MockHandler and real Illuminate 10 components. PHP syntax and whitespace checks passed.
The original Testbench suite could not install because Composer's advisory policy rejects its supported Laravel releases. Live synthesis and the full supported-version matrix were not tested.