bug: `session.interrupt` command requires two sends

Describe the bug

When we send the session.interrupt command, the opencode TUI displays "press Esc again to interrupt".

I think this regressed with opencode v1.0 because it used to work immediately.

Steps To Reproduce

1. Send a message to opencode so it begins responding
2. Select session.interrupt command from opencode.nvim
3. Must repeat step 2 to actually interrupt.

Expected Behavior

Selecting session.interrupt command a single time interrupts opencode.

Normally I don't like to work around opencode bugs, but this one is simple.

See lua/opencode/api/command.lua