feat: integrate OpenTelemetry

[tianhuil]

Hi @thdxr, @adamdotdevin, and @rekram1-node

I love opencode. Trying to run it with open telemetry and wanted to add back some code to the project. If you generaly like this commit, I can work on resolving the merge conflict (just imports, nothing big).

Summary

• Integrate OpenTelemetry for enhanced tracing and monitoring capabilities
• Add type annotations to execute and toModelOutput methods in SessionPrompt

Changes

• Added OpenTelemetry dependencies for comprehensive observability
• Fixed type annotations in SessionPrompt methods for better type safety
• Updated package lock file with new dependencies

[rekram1-node]

I think opencode already emits telemetry spans if you set:

experimental_opentelemetry to true in your opencode.json

[tianhuil]

Thanks for the quick response @rekram1-node.

I set the following and it didn't work:

//.opencode/opencode.jsonc
{
  "$schema": "https://opencode.ai/config.json",
  "experimental": {
    "openTelemetry": true
  },
}

I had to modify the repo to get it to emit open telemetry.