Support Nova Sonic

[tbrand]

Description of Changes

For bidirectional communication, I'm currently using AppSync Event API. However, since limit exceeds errors occur frequently, I'm buffering more than necessary. I'm using AppSync Event API to maintain a serverless architecture, but if I determine it's difficult during the trial period, I may switch to a different implementation.

Let me explain the handshake flow. The client generates a channel ID and connects to that channel (via AppSync).
The server invokes a Lambda task with the channel ID as a parameter. Lambda then connects to AppSync accordingly, and after connecting, sends a notification that it's ready to AppSync. Once the client receives the ready notification, it begins transmitting audio.

Architecture Concerns

• Lambda execution time limit is 15 minutes. Nova Sonic's maximum session time is 8 minutes, so currently this is not a bottleneck for execution time.
  • https://aws.amazon.com/blogs/aws/introducing-amazon-nova-sonic-human-like-voice-conversations-for-generative-ai-applications/
• AppSync Events quota. Maximum of 50 channels under a namespace. Since Nova Sonic itself is limited to 20 concurrent executions, this is not currently a bottleneck.
  • https://docs.aws.amazon.com/ja_jp/general/latest/gr/appsync.html
  • https://docs.aws.amazon.com/general/latest/gr/bedrock.html

Checklist

• Executed npm run lint
• Modified relevant documentation
• Verified operation in local environment
• Executed npm run cdk:test and if there are snapshot differences, execute npm run cdk:test:update-snapshot to update snapshots

Related Issues

#990

[maekawataiki]

LGTM!