Reload inbox after merge + pull-to-refresh on PR content; bump to 3.4

- After a merge, the app returns to the landing page but the inbox kept stale
  PRs. Add an inboxNeedsRefresh flag set on merge success; InboxView reloads
  on next appearance when it's set.
- The PR content (incl. the Checks/workflow tab) is now pull-to-refreshable
  via .refreshable on the content ScrollView, so workflow status can be
  updated by pulling down. Bump to 3.4.

GiteaPR/Settings/SettingsStore.swift

@@ -33,6 +33,9 @@ final class SettingsStore: ObservableObject {
         didSet { UserDefaults.standard.set(monitoredRepos,
                                            forKey: "monitoredRepos") }
     }
+    /// Set when a PR is merged, so the inbox knows to reload on next appearance
+    /// (otherwise a just-merged PR could linger as stale in the list).
+    @Published var inboxNeedsRefresh = false
 
     private init() {
         instanceURL = KeychainHelper.get("instanceURL") ?? "https://gitea.bueso.eu"