Add separator to site header (#25403)

Author: kean

WordPress/Classes/ViewRelated/Reader/Headers/ReaderSiteHeaderView.swift

@@ -15,13 +15,28 @@ class ReaderSiteHeaderView: ReaderBaseHeaderView, ReaderStreamHeader {
         })
     }()
 
+    private let separatorView: UIView = {
+        let view = UIView()
+        view.backgroundColor = .separator
+        return view
+    }()
+
     override init(frame: CGRect) {
         super.init(frame: frame)
 
         let header = ReaderSiteHeader(viewModel: headerViewModel)
         let view = UIView.embedSwiftUIView(header)
         contentView.addSubview(view)
         view.pinEdges()
+
+        addSubview(separatorView)
+        separatorView.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            separatorView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            separatorView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            separatorView.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -8),
+            separatorView.heightAnchor.constraint(equalToConstant: 1)
+        ])
     }
 
     required init?(coder: NSCoder) {