sessions-index.json not updated by SDK, only by CLI

The Claude Code CLI stores meta-data for each session it creates or updates in `~/.claude/projects//sessions-index.json`.
When using the SDK to resume any of the sessions in the project directory or create new ones, the `sessions-index.json` is not updated.
This breaks the ability to use the SDK and the Claude Code CLI interchangebly - after using the SDK it's not possible to resume in the CLI any of the sessions created by the SDK since they won't appear in the index file.

Steps to reproduce:

```
import { query } from '@anthropic-ai/claude-agent-sdk';
const q = query({
prompt: 'What is 1 + 1?'
});
for await (const msg of q) {
console.log(msg);
}
```

observe how the `sessions-index.json` file for the project is not updated or created if it's missing