Add first-class Actions management (#63)

ios/Sources/PullScreens.swift

@@ -62,7 +62,7 @@ final class PullsViewController: RefreshingTableViewController {
     init(context: AppContext) {
         self.context = context
         super.init()
-        title = "Pull Requests"
+        setPanelTitle(self, "Pull Requests", server: context.core.activeServerName())
     }
 
     @available(*, unavailable)
@@ -75,20 +75,28 @@ final class PullsViewController: RefreshingTableViewController {
         tableView.register(PullCell.self, forCellReuseIdentifier: "pull")
         tableView.rowHeight = UITableView.automaticDimension
         tableView.estimatedRowHeight = 116
-        navigationItem.leftBarButtonItem = UIBarButtonItem(
-            image: context.symbol("server.rack"),
-            primaryAction: UIAction { [weak self] _ in
-                guard let self else { return }
-                self.navigationController?.pushViewController(
-                    ServersViewController(context: self.context),
-                    animated: true
-                )
-            }
-        )
         updateFilterMenu()
         loadContent(refreshing: false)
     }
 
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        if navigationController?.viewControllers.first === self {
+            navigationItem.leftBarButtonItem = UIBarButtonItem(
+                image: context.symbol("server.rack"),
+                primaryAction: UIAction { [weak self] _ in
+                    guard let self else { return }
+                    self.navigationController?.pushViewController(
+                        ServersViewController(context: self.context),
+                        animated: true
+                    )
+                }
+            )
+        } else {
+            navigationItem.leftBarButtonItem = nil
+        }
+    }
+
     override func loadContent(refreshing: Bool) {
         guard context.core.activeServerIndex() != nil else {
             tableView.backgroundView = EmptyBackgroundView(