Support /side command in the IDE Extension

What variant of Codex are you using?

IDE Extension

What feature would you like to see?

This issue is specifically requesting /side.
/side is one of the most useful workflow features in Codex CLI.

It allows users to temporarily explore a different topic or investigate an idea without polluting the main conversation context.

For example:

• Asking an unrelated conceptual question while implementing a feature
• Investigating an alternative implementation
• Debugging an issue that may turn out to be unrelated
• Reading documentation or exploring APIs before returning to the original task

Without /side, these conversations become part of the main session, making the context larger and less focused.

Expected behavior

The VS Code extension should support /side with behavior consistent with Codex CLI.

Ideally, users should be able to:

• Start a side conversation with /side
• Keep the main session context unchanged
• Return to the original conversation after the exploration

Maintaining feature parity between the CLI and the VS Code extension would make switching between the two much more seamless.

Thanks for considering this!

Additional information

_No response_