Rename Google Voice config to recipients

[Pigbibi]

Summary

• rename Google Voice notification destination config from gateway to recipients
• document that recipients are email-form addresses: normal mailboxes receive email, Google Voice mailboxes/addresses can also trigger GV prompts
• update QPK and strategy dependency pins to the recipients config commits
• keep old GOOGLE_VOICE_TO and GOOGLE_VOICE_GATEWAY env names in Cloud Run cleanup lists

Tests

• PYTHONPATH=/home/ubuntu/Projects/QuantPlatformKit/src:/home/ubuntu/Projects/UsEquityStrategies/src:. .venv/bin/python -m pytest tests/test_runtime_config_support.py tests/test_request_handling.py
• bash tests/test_sync_cloud_run_env_workflow.sh
• .venv/bin/python -m ruff check .