Unify home sidebar and top bar chrome colors.

This makes the left navigation background use the same shared chrome color as the top bar to keep the home header/sidebar visual treatment consistent.

Made-with: Cursor

zoom_app/ViewController.swift

@@ -967,7 +967,7 @@ class ViewController: NSViewController {
     private func makeSidebar(items: [String], selected: String, style: SidebarStyle = .login) -> NSView {
         let sidebar = NSView()
         sidebar.wantsLayer = true
-        sidebar.layer?.backgroundColor = (style == .home ? NSColor.white.withAlphaComponent(0.03) : sidebarBackground).cgColor
+        sidebar.layer?.backgroundColor = (style == .home ? chromeUnifiedBackground : sidebarBackground).cgColor
 
         let stack = NSStackView()
         stack.orientation = .vertical