feat: add shunya transcriber

[RG-04]

No description provided.

To fix the problem, the code should stop logging the full init_msg including the api_key. Instead, log only non-sensitive parts of the initialization message, or simply confirm that the message was sent without including its content. This preserves observability (knowing that an init message was sent) while eliminating exposure of the API key.

The best minimal fix without changing existing functionality is:

• Keep _create_init_message unchanged so the WebSocket still receives the full configuration, including api_key.
• Change the log statement on line 265 so it no longer includes json.dumps(init_msg). Optionally, log a filtered view of init_msg with the api_key omitted or masked.

Concretely:

• In bolna/transcriber/shunya_transcriber.py, locate the block where init_msg is created and sent:
  • Line 263: init_msg = self._create_init_message()
  • Line 264: await ws.send(json.dumps(init_msg))
  • Line 265: logger.info(f"Sent initialization message to Shunya Labs, {json.dumps(init_msg)}")
• Replace line 265 with a safe logging statement that either:
  • logs just a static message (most conservative), or
  • logs a redacted/partial version of the config (e.g., language, model, and api_key replaced with "***").

No new methods or imports are strictly required; we can construct a small redacted dict inline if desired. To stay simple and robust, I’ll log only non-sensitive configuration fields (language, model, frames_silence_duration) and omit the key entirely.