Add issue creation and editing

ios/Sources/ContentScreens.swift

@@ -8,6 +8,9 @@ final class IssuesViewController: RefreshingTableViewController {
     private var rows: [IssueRow] = []
     private var filterOptions: IssueFilterOptions?
     private var filterTask: Task<Void, Never>?
+    private lazy var filterButton = UIBarButtonItem(
+        image: context.symbol("line.3.horizontal.decrease.circle")
+    )
 
     init(context: AppContext, owner: String, repository: String) {
         self.context = context
@@ -25,6 +28,13 @@ final class IssuesViewController: RefreshingTableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.register(IssueCell.self, forCellReuseIdentifier: "issue")
+        let addButton = UIBarButtonItem(
+            barButtonSystemItem: .add,
+            target: self,
+            action: #selector(createIssue)
+        )
+        addButton.accessibilityLabel = "New issue"
+        navigationItem.rightBarButtonItems = [addButton, filterButton]
         updateFilterMenu()
         loadContent(refreshing: false)
     }
@@ -122,14 +132,8 @@ final class IssuesViewController: RefreshingTableViewController {
         } else {
             children.append(UIAction(title: "Loading filters…", attributes: .disabled) { _ in })
         }
-        let item = navigationItem.rightBarButtonItem ?? UIBarButtonItem(
-            image: context.symbol("line.3.horizontal.decrease.circle")
-        )
-        item.menu = UIMenu(children: children)
-        item.accessibilityLabel = "Filter issues"
-        if navigationItem.rightBarButtonItem == nil {
-            navigationItem.rightBarButtonItem = item
-        }
+        filterButton.menu = UIMenu(children: children)
+        filterButton.accessibilityLabel = "Filter issues"
         updateFilterTint()
     }
 
@@ -211,12 +215,35 @@ final class IssuesViewController: RefreshingTableViewController {
     }
 
     private func updateFilterTint() {
-        navigationItem.rightBarButtonItem?.tintColor = filtersActive ? .tintColor : .secondaryLabel
-        navigationItem.rightBarButtonItem?.accessibilityValue = filtersActive
+        filterButton.tintColor = filtersActive ? .tintColor : .secondaryLabel
+        filterButton.accessibilityValue = filtersActive
             ? "Filters active"
             : "Default filters"
     }
 
+    @objc private func createIssue() {
+        let editor = IssueEditorViewController(
+            context: context,
+            owner: owner,
+            repository: repository
+        ) { [weak self] number in
+            guard let self else { return }
+            self.dismiss(animated: true) {
+                self.loadContent(refreshing: false)
+                self.navigationController?.pushViewController(
+                    IssueViewController(
+                        context: self.context,
+                        owner: self.owner,
+                        repository: self.repository,
+                        number: number
+                    ),
+                    animated: true
+                )
+            }
+        }
+        present(UINavigationController(rootViewController: editor), animated: true)
+    }
+
     private func updateEmptyState() {
         guard rows.isEmpty else {
             tableView.backgroundView = nil