You're encountering a common issue with macOS menu-bar apps: **the menu doesn't appear when the status item is clicked**, even though the code looks correct. Let's analyze and fix the problem.

---

### 🔍 **Root Cause**

The issue lies in this line:

```swift
statusItem.button?.performClick(nil)
```

This line **does not actually show the menu**. In fact, `performClick()` is not the correct way to display a menu. The `NSStatusItem`'s menu is shown automatically when the user clicks the status item **if** the `menu` property is set **before** the click.

But more importantly, **you're setting the menu, then immediately clearing it**:

```swift
statusItem.menu = menu
statusItem.button?.performClick(nil)
statusItem.menu = nil  // ← This is the problem!
```

You're **removing the menu immediately after setting it**, so the menu never has a chance to be displayed.

---

### ✅ **Fix**

Remove the line that clears the menu:

```swift
private func showMenu() {
    let menu = NSMenu()
    menu.addItem(withTitle: "Open", action: #selector(open), keyEquivalent: "")
    menu.addItem(withTitle: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
    statusItem.menu = menu
    // Remove this line:
    // statusItem.menu = nil
}
```

Also, **you don't need to call `performClick()`** — the menu will appear automatically when the user clicks the status item **if** the menu is set.

But wait — you're calling `showMenu()` from `statusClicked`, which is triggered by a click. So if you're already in the click handler, you don't need to simulate a click.

---

### 🛠️ **Additional Fixes & Best Practices**

1. **Ensure `statusItem.menu` is set before the user clicks.**
2. **Don’t clear the menu immediately.**
3. **Make sure the menu is set before the click event.**
4. **Avoid calling `performClick()` unless you're simulating a click.**

---

### ✅ **Corrected Code**

```swift
private func buildStatusItem() {
    statusItem = NSStatusBar.system.statusItem(withLength: NSStatusItem.variableLength)
    statusItem.button?.image = NSImage(systemSymbolName: "star", accessibilityDescription: nil)
    statusItem.button?.action = #selector(statusClicked)
    statusItem.button?.target = self
    // No need to sendAction on specific events — it's handled by the button
}

@objc private func statusClicked() {
    if let event = NSApp.currentEvent, event.type == .rightMouseUp {
        showMenu()
    } else {
        togglePanel()
    }
}

private func showMenu() {
    let menu = NSMenu()
    menu.addItem(withTitle: "Open", action: #selector(open), keyEquivalent: "")
    menu.addItem(withTitle: "Quit", action: #selector(NSApplication.terminate(_:)), keyEquivalent: "q")
    statusItem.menu = menu
    // Do NOT set menu to nil here!
    // The menu will be cleared automatically when it's dismissed
}
```

---

### 🧪 **Testing**

1. **Build and run the app.**
2. **Click the status item:**
   - Left-click → should toggle your panel.
   - Right-click → should show the menu with "Open" and "Quit".
3. **Verify:**
   - Menu appears on right-click.
   - "Quit" works.
   - No crashes or errors.

---

### 📝 **Bonus Tips**

- **Use `NSMenu`'s `autoenablesItems` and `autoenablesItems`** if needed.
- **Ensure `statusItem` is retained** (e.g., stored as a property) — otherwise it may be deallocated.
- **Avoid setting `menu` to `nil` unless you want to clear it.**
- **Consider using `NSMenu`'s `popUp` method** if you want to show a menu programmatically without relying on the status item click.

---

### ✅ Final Fix Summary

> ❌ **Wrong:**  
> ```swift
> statusItem.menu = menu
> statusItem.button?.performClick(nil)
> statusItem.menu = nil
> ```

> ✅ **Correct:**  
> ```swift
> statusItem.menu = menu
> // No need to call performClick or clear menu
> ```

Now the menu should appear on right-click. 🎉