feat(menubar): polish the status-item menu and About tab (#509)

Right-click menu:
- Add a dimmed "Today · $X · N calls" usage row at the top.
- Give Settings an explicit gearshape icon (instead of relying on the macOS
  Tahoe auto-decoration).
- Add an "About CodeBurn" item that opens Settings on the About tab.
- Drop the per-item keyboard-shortcut labels and the section separators for a
  flat, compact list.
- Open the menu a few px below the status item so it clears the menu bar
  (anchoring flush clipped the top edge and triggered menu scrolling on hover).

Settings:
- Add a settingsTab selection to AppStore and bind SettingsView's TabView to
  it (tagged tabs) so "About CodeBurn" can jump straight to the About tab.
- About tab: add a "Star on GitHub" button and a "Sponsor" link.

mac/Sources/CodeBurnMenubar/AppStore.swift

@@ -52,6 +52,9 @@ final class AppStore {
     }
     var showingAccentPicker: Bool = false
     var currency: String = "USD"
+    /// Which Settings tab to show; lets the menu's "About CodeBurn" item jump
+    /// straight to the About tab even when the Settings window is reused.
+    var settingsTab: String = "general"
     var displayMetric: DisplayMetric = DisplayMetric(rawValue: UserDefaults.standard.string(forKey: "CodeBurnDisplayMetric") ?? "") ?? .cost {
         didSet { UserDefaults.standard.set(displayMetric.rawValue, forKey: "CodeBurnDisplayMetric") }
     }

mac/Sources/CodeBurnMenubar/CodeBurnApp.swift

@@ -857,31 +857,56 @@ final class AppDelegate: NSObject, NSApplicationDelegate, NSPopoverDelegate {
 
         let menu = NSMenu()
 
-        let settingsItem = NSMenuItem(title: "Settings…", action: #selector(openSettings), keyEquivalent: ",")
+        // Glanceable "today" usage at the top as a single non-interactive (dimmed)
+        // row. A real .sectionHeader adds section padding (and pulls the actions
+        // into its group without a separator), so use a plain disabled item.
+        let usageItem = NSMenuItem(title: contextMenuUsageSummary(), action: nil, keyEquivalent: "")
+        usageItem.isEnabled = false
+        menu.addItem(usageItem)
+
+        let settingsItem = NSMenuItem(title: "Settings…", action: #selector(openSettings), keyEquivalent: "")
         settingsItem.target = self
+        settingsItem.image = NSImage(systemSymbolName: "gearshape", accessibilityDescription: "Settings")
         menu.addItem(settingsItem)
 
-        let refreshNow = NSMenuItem(title: "Refresh Now", action: #selector(refreshNowAction), keyEquivalent: "r")
+        let refreshNow = NSMenuItem(title: "Refresh Now", action: #selector(refreshNowAction), keyEquivalent: "")
         refreshNow.target = self
         menu.addItem(refreshNow)
 
-        menu.addItem(.separator())
         let updateItem = NSMenuItem(title: "Check for Updates", action: #selector(checkForUpdates), keyEquivalent: "")
         updateItem.target = self
         menu.addItem(updateItem)
-        menu.addItem(.separator())
-        let quitItem = NSMenuItem(title: "Quit CodeBurn", action: #selector(quitApp), keyEquivalent: "q")
+
+        let aboutItem = NSMenuItem(title: "About CodeBurn", action: #selector(openAbout), keyEquivalent: "")
+        aboutItem.target = self
+        menu.addItem(aboutItem)
+
+        let quitItem = NSMenuItem(title: "Quit CodeBurn", action: #selector(quitApp), keyEquivalent: "")
         quitItem.target = self
         menu.addItem(quitItem)
 
         // Present directly. The previous `statusItem.menu = menu; button.performClick`
         // trick relies on the click -> action path that macOS 27 changed; popUp is
-        // version-stable.
-        menu.popUp(positioning: nil, at: NSPoint(x: 0, y: button.bounds.height + 4), in: button)
+        // version-stable. Open a few px below the status item so the menu clears the
+        // menu bar: anchoring flush clips the top edge and makes macOS engage menu
+        // scrolling (a scroll chevron appears and the first row slides up on hover).
+        menu.popUp(positioning: nil, at: NSPoint(x: 0, y: button.bounds.height + 6), in: button)
+    }
+
+    /// One-line "today" summary for the context menu's usage row.
+    private func contextMenuUsageSummary() -> String {
+        guard let current = store.todayPayload?.current else { return "Today · no usage yet" }
+        let calls = current.calls == 1 ? "1 call" : "\(current.calls) calls"
+        return "Today · \(current.cost.asCurrency()) · \(calls)"
     }
 
     private var settingsWindowController: NSWindowController?
 
+    @objc private func openAbout() {
+        store.settingsTab = "about"
+        openSettings()
+    }
+
     @objc private func openSettings() {
         // Accessory-policy apps (no Dock icon, no main menu) don't get the
         // SwiftUI Settings scene wired into the responder chain reliably, so

mac/Sources/CodeBurnMenubar/Views/SettingsView.swift

@@ -8,21 +8,26 @@ struct SettingsView: View {
     @Environment(AppStore.self) private var store
 
     var body: some View {
-        TabView {
+        TabView(selection: Binding(get: { store.settingsTab }, set: { store.settingsTab = $0 })) {
             GeneralSettingsTab()
                 .tabItem { Label("General", systemImage: "gearshape") }
+                .tag("general")
 
             ClaudeSettingsTab()
                 .tabItem { Label("Claude", systemImage: "brain") }
+                .tag("claude")
 
             CodexSettingsTab()
                 .tabItem { Label("Codex", systemImage: "chevron.left.forwardslash.chevron.right") }
+                .tag("codex")
 
             DevinSettingsTab()
                 .tabItem { Label("Devin", systemImage: "flame.fill") }
+                .tag("devin")
 
             AboutSettingsTab()
                 .tabItem { Label("About", systemImage: "info.circle") }
+                .tag("about")
         }
         .frame(width: 520, height: 430)
     }
@@ -660,9 +665,16 @@ private struct AboutSettingsTab: View {
             Text("Version \(appVersion) (\(buildVersion))")
                 .font(.codeMono(size: 11))
                 .foregroundStyle(.secondary)
+            Link(destination: URL(string: "https://github.com/getagentseal/codeburn")!) {
+                Label("Star on GitHub", systemImage: "star.fill")
+                    .font(.system(size: 12, weight: .medium))
+            }
+            .buttonStyle(.borderedProminent)
+            .tint(Theme.brandAccent)
             HStack(spacing: 10) {
                 Link("GitHub", destination: URL(string: "https://github.com/getagentseal/codeburn")!)
                 Link("Issues", destination: URL(string: "https://github.com/getagentseal/codeburn/issues")!)
+                Link("Sponsor", destination: URL(string: "https://github.com/sponsors/iamtoruk")!)
             }
             .font(.system(size: 12))
         }