Fix OAuth MainActor await warning, hover closures, WKWebView layout

Use MainActor.run for synchronous openAuthURLInApp to satisfy await.
Replace unused guard let self with guard self != nil in meet card hovers.
Lay out OAuth WKWebView with frame-based container to avoid Auto Layout conflicts.

Made-with: Cursor

classroom_app/Auth/GoogleOAuthService.swift

@@ -154,7 +154,10 @@ final class GoogleOAuthService: NSObject {
         ]
 
         guard let authURL = components.url else { throw GoogleOAuthError.invalidCallbackURL }
-        guard await openAuthURLInApp(authURL) else { throw GoogleOAuthError.unableToOpenBrowser }
+        let opened = await MainActor.run { [self] in
+            openAuthURLInApp(authURL)
+        }
+        guard opened else { throw GoogleOAuthError.unableToOpenBrowser }
         defer {
             Task { @MainActor [weak self] in
                 self?.closeInAppOAuthWindow()
@@ -489,6 +492,28 @@ extension GoogleOAuthError: LocalizedError {
     }
 }
 
+@MainActor
+private final class OAuthWebViewContainerView: NSView {
+    private let webView: WKWebView
+
+    init(webView: WKWebView) {
+        self.webView = webView
+        super.init(frame: .zero)
+        autoresizingMask = [.width, .height]
+        addSubview(webView)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        nil
+    }
+
+    override func layout() {
+        super.layout()
+        webView.frame = bounds
+    }
+}
+
 @MainActor
 private final class InAppOAuthWindowController: NSWindowController, WKNavigationDelegate, WKUIDelegate {
     private let webView: WKWebView
@@ -499,17 +524,8 @@ private final class InAppOAuthWindowController: NSWindowController, WKNavigation
             config.defaultWebpagePreferences.allowsContentJavaScript = true
         }
         self.webView = WKWebView(frame: .zero, configuration: config)
-        webView.translatesAutoresizingMaskIntoConstraints = false
-
-        let container = NSView()
-        container.translatesAutoresizingMaskIntoConstraints = false
-        container.addSubview(webView)
-        NSLayoutConstraint.activate([
-            webView.leadingAnchor.constraint(equalTo: container.leadingAnchor),
-            webView.trailingAnchor.constraint(equalTo: container.trailingAnchor),
-            webView.topAnchor.constraint(equalTo: container.topAnchor),
-            webView.bottomAnchor.constraint(equalTo: container.bottomAnchor)
-        ])
+        // Frame-based layout avoids Auto Layout conflicts with WKWebView’s internal constraints.
+        let container = OAuthWebViewContainerView(webView: webView)
 
         let window = NSWindow(
             contentRect: NSRect(x: 0, y: 0, width: 980, height: 760),

classroom_app/ViewController.swift

@@ -2750,12 +2750,12 @@ private extension ViewController {
         let hoverColor = baseColor.blended(withFraction: darkModeEnabled ? 0.24 : 0.16, of: classroomHoverTint) ?? baseColor
         let hoverBorderColor = baseBorderColor.blended(withFraction: darkModeEnabled ? 0.45 : 0.32, of: classroomHoverTint) ?? baseBorderColor
         instant.onHoverChanged = { [weak self] hovering in
-            guard let self else { return }
+            guard self != nil else { return }
             instant.layer?.backgroundColor = (hovering ? hoverColor : baseColor).cgColor
             instant.layer?.borderColor = (hovering ? hoverBorderColor : baseBorderColor).cgColor
         }
         codeCard.onHoverChanged = { [weak self] hovering in
-            guard let self else { return }
+            guard self != nil else { return }
             codeCard.layer?.backgroundColor = (hovering ? hoverColor : baseColor).cgColor
             codeCard.layer?.borderColor = (hovering ? hoverBorderColor : baseBorderColor).cgColor
         }