Track follow-ups from Moira's review on warp-external#908 — "Fix stale View menu shortcut when left panel is hidden".

Review comments to address

1. Logic refactor — app/src/app_menus.rs:1189 (inline comment)

this feels like a code smell that something isn't right in the logic because we shouldn't need to special case if the keystroke is none. we should semantically just be reflecting what the binding is at that point in time. here's a convo i had w agent mode exploring potential solutions: https://staging.warp.dev/conversation/7b56a3bc-60c2-4f53-bb01-756becd3009e

Rework the fix so the View menu simply reflects the current binding rather than special-casing the "no keystroke" case. See Moira's linked agent conversation for potential solutions.

2. Add Left Panel: Warp Drive menu item (review comment)

one more thing, i know Drive is its own menu entity but i think we should have Left Panel: Warp Drive as a menu item here

Even though Drive is its own top-level menu entity, add a Left Panel: Warp Drive entry in the View menu alongside the other left-panel toggles for consistency.

Linear: APP-4184