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/Detail/PRDetailView.swift

@@ -70,8 +70,9 @@ struct PRDetailView: View {
         }
         .sheet(isPresented: $showMergeSheet) {
             MergeSheet(vm: vm) {
-                // Merge succeeded: show the success animation, then pop back
-                // to the landing page.
+                // Merge succeeded: mark the inbox for refresh, show the success
+                // animation, then pop back to the landing page.
+                SettingsStore.shared.inboxNeedsRefresh = true
                 withAnimation(.spring(response: 0.4, dampingFraction: 0.6)) {
                     showMergeSuccess = true
                 }
@@ -114,6 +115,7 @@ struct PRDetailView: View {
                 case .none: OverviewTab(pr: pr)
                 }
             }
+            .refreshable { await vm.load() }
 
             bottomTabBar
         }