Bug: "shift-up-arrow" inside an editor does extend selection up

[jlewi]

If you hit "shift-up-arrow" while inside a monaco editor for a cell I'd expect it to extend the current selection up one line.
I suspect #197 broke this because that changed "shift-up-arrow/down-arrow" to be used by app console

buildDate: "2026-05-03T22:31:09Z"
webRepo: runmedev/web
webBranch: main
webCommit: 406e464
codexRepo: openai/codex
codexBranch: dev/jlewi/wasm
codexCommit: 78cdff946581323dbe81032e3b620a7000080b80
bucket: gs://runme-hosted