Added install instructions, and version check

oAI/Views/Main/FooterView.swift

@@ -80,6 +80,11 @@ struct FooterView: View {
                 )
             }
 
+            // Update available badge
+            #if os(macOS)
+            UpdateBadge()
+            #endif
+
             // Shortcuts hint
             #if os(macOS)
             Text("⌘N New • ⌘M Model • ⌘⇧S Save")
@@ -254,6 +259,32 @@ struct SyncStatusFooter: View {
     }
 }
 
+struct UpdateBadge: View {
+    private let updater = UpdateCheckService.shared
+    private let currentVersion = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "?"
+
+    var body: some View {
+        if updater.updateAvailable {
+            Button(action: { updater.openReleasesPage() }) {
+                HStack(spacing: 4) {
+                    Image(systemName: "arrow.up.circle.fill")
+                        .font(.system(size: 10))
+                    Text("Update Available\(updater.latestVersion.map { " (v\($0))" } ?? "")")
+                        .font(.caption2)
+                        .fontWeight(.medium)
+                }
+                .foregroundColor(.green)
+            }
+            .buttonStyle(.plain)
+            .help("A new version is available — click to open the releases page")
+        } else {
+            Text("v\(currentVersion)")
+                .font(.caption2)
+                .foregroundColor(.oaiSecondary)
+        }
+    }
+}
+
 #Preview {
     let stats = SessionStats(
         totalInputTokens: 1250,