Fix: Escape exits Zen Mode when pressed in Normal mode

[bouclem]

Fixes #9981

When in Zen Mode with Vim active, pressing Escape while focused on a file tab never reaches VS Code's native Zen Mode exit handler. Vim intercepts the key and the Esc, Esc sequence to exit Zen Mode does nothing.

Cause

CommandEsc in Normal mode already calls a set of VS Code cleanup commands (close reference search, close markers, hide inline suggestions, etc.) via Promise.allSettled. workbench.action.exitZenMode was missing from that list.

Change

• Added workbench.action.exitZenMode to the existing cleanup commands in CommandEsc.exec() for Normal mode

This means:

• From Insert mode: first Esc goes to Normal, second Esc exits Zen Mode (matches VS Code's double-Esc behavior)
• From Normal mode: Esc exits Zen Mode directly (Vim has nothing else to do with it)
• Outside Zen Mode: the command is a no-op, no side effects