Quick Look file preview (QLPreviewPanel)

[senatov]

Add Quick Look preview for the selected file, triggered by spacebar (like Finder).

Context: QuickLookService.shared.preview(file:) already exists and is called from context menu. This issue is about adding the spacebar shortcut and ensuring smooth integration.

Relevant files:

• FileTableView+Actions.swift — keyboard handling
• HotKeys/ — shortcut definitions
• FileActionsHandler.swift — openQuickLook()

Difficulty: ⭐⭐