Enable settings window minimization

Sources/CodexBar/PreferencesView.swift

@@ -371,6 +371,9 @@ final class SettingsWindowAppearanceView: NSView {
         if !window.styleMask.contains(.resizable) {
             window.styleMask.insert(.resizable)
         }
+        if !window.styleMask.contains(.miniaturizable) {
+            window.styleMask.insert(.miniaturizable)
+        }
         if !window.titlebarAppearsTransparent {
             window.titlebarAppearsTransparent = true
         }

Tests/CodexBarTests/SettingsWindowAppearanceTests.swift

@@ -198,6 +198,22 @@ struct SettingsWindowAppearanceTests {
         #expect(window.styleMask.contains(.resizable))
     }
 
+    @Test
+    func `settings window style enables minimization`() {
+        let bridge = SettingsWindowAppearanceView()
+        let window = NSWindow(
+            contentRect: NSRect(x: 0, y: 0, width: 400, height: 300),
+            styleMask: [.titled],
+            backing: .buffered,
+            defer: false)
+
+        window.contentView = bridge
+
+        #expect(window.styleMask.contains(.miniaturizable))
+        #expect(window.isMiniaturizable)
+        #expect(window.standardWindowButton(.miniaturizeButton)?.isEnabled == true)
+    }
+
     @Test
     func `settings window extends content behind the titlebar for the edge-to-edge sidebar`() {
         let bridge = SettingsWindowAppearanceView()