Fix iOS WebKit crash by shipping external app.js instead of inlined HTML.

Stop embedding the 1.4MB bundle in index.html to avoid std::overflow_error on launch, validate the iOS asset build, and surface load failures in the native shell.

Co-authored-by: Cursor <cursoragent@cursor.com>

ios/WordLoop/WordLoop/Views/WordLoopWebView.swift

@@ -6,6 +6,7 @@ final class WebViewStore: ObservableObject {
     @Published var isLoading = true
     @Published var canGoBack = false
     @Published var pageTitle = "WordLoop"
+    @Published var loadError: String?
     weak var webView: WKWebView?
     var schemeHandler: BundleWebSchemeHandler?
 }
@@ -92,26 +93,23 @@ struct WordLoopWebView: UIViewRepresentable {
             loadedEntryURL = entryURL
             loadedAPIBaseURL = apiBaseURL
             pendingAPIBaseURL = apiBaseURL
-            store.isLoading = true
+            Task { @MainActor in
+                store.isLoading = true
+                store.loadError = nil
+            }
 
-            if usesBundledFrontend, let bundleEntry = Self.bundledHTMLPayload() {
-                // loadHTMLString 比 wordloop:// 自定义协议更可靠（WKWebView 对内联/外链脚本执行更稳定）
-                webView.loadHTMLString(bundleEntry.html, baseURL: bundleEntry.baseURL)
+            if usesBundledFrontend,
+               let wwwRoot = ServerSettings.bundledWWWDirectory,
+               let indexURL = ServerSettings.bundledHomeURL {
+                let readAccess = ServerSettings.bundledReadAccessURL() ?? wwwRoot
+                webView.loadFileURL(indexURL, allowingReadAccessTo: readAccess)
+            } else if let remoteURL = ServerSettings.homeURL(for: apiBaseURL) {
+                webView.load(URLRequest(url: remoteURL, cachePolicy: .reloadIgnoringLocalCacheData))
             } else {
                 webView.load(URLRequest(url: entryURL, cachePolicy: .reloadIgnoringLocalCacheData))
             }
         }
 
-        private static func bundledHTMLPayload() -> (html: String, baseURL: URL)? {
-            guard let wwwRoot = ServerSettings.bundledWWWDirectory,
-                  let indexURL = ServerSettings.bundledHomeURL,
-                  let html = try? String(contentsOf: indexURL, encoding: .utf8),
-                  !html.isEmpty else {
-                return nil
-            }
-            return (html, wwwRoot)
-        }
-
         func updateAPIBase(_ apiBaseURL: String, in webView: WKWebView) {
             guard loadedAPIBaseURL != apiBaseURL else { return }
             loadedAPIBaseURL = apiBaseURL
@@ -126,26 +124,43 @@ struct WordLoopWebView: UIViewRepresentable {
         }
 
         func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
-            store.isLoading = true
-            store.canGoBack = webView.canGoBack
+            Task { @MainActor in
+                store.isLoading = true
+                store.canGoBack = webView.canGoBack
+            }
         }
 
         func webView(_ webView: WKWebView, didFail navigation: WKNavigation!, withError error: Error) {
-            store.isLoading = false
-            store.canGoBack = webView.canGoBack
+            Task { @MainActor in
+                store.isLoading = false
+                store.canGoBack = webView.canGoBack
+                store.loadError = error.localizedDescription
+            }
         }
 
         func webView(_ webView: WKWebView, didFailProvisionalNavigation navigation: WKNavigation!, withError error: Error) {
-            store.isLoading = false
-            store.canGoBack = webView.canGoBack
+            Task { @MainActor in
+                store.isLoading = false
+                store.canGoBack = webView.canGoBack
+                store.loadError = error.localizedDescription
+            }
         }
 
         func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
-            store.isLoading = false
-            store.canGoBack = webView.canGoBack
-            store.pageTitle = webView.title ?? "WordLoop"
-            if let apiBaseURL = pendingAPIBaseURL {
-                updateAPIBase(apiBaseURL, in: webView)
+            Task { @MainActor in
+                store.isLoading = false
+                store.canGoBack = webView.canGoBack
+                store.pageTitle = webView.title ?? "WordLoop"
+                if let apiBaseURL = pendingAPIBaseURL {
+                    updateAPIBase(apiBaseURL, in: webView)
+                }
+            }
+            webView.evaluateJavaScript("document.getElementById('app')?.innerHTML?.length ?? 0") { [weak self] result, _ in
+                let appLen = (result as? NSNumber)?.intValue ?? 0
+                guard appLen <= 0 else { return }
+                Task { @MainActor in
+                    self?.store.loadError = "页面未渲染，请删除 App 后重新安装"
+                }
             }
         }
     }
@@ -197,7 +212,24 @@ struct WordLoopWebContainer: View {
                     )
                     .ignoresSafeArea(edges: .bottom)
 
-                    if store.isLoading {
+                    if let loadError = store.loadError {
+                        VStack(spacing: 12) {
+                            Text("页面加载失败")
+                                .font(.headline)
+                            Text(loadError)
+                                .font(.caption)
+                                .foregroundStyle(.secondary)
+                                .multilineTextAlignment(.center)
+                            Button("重新加载") {
+                                store.loadError = nil
+                                store.webView?.reload()
+                            }
+                            .buttonStyle(.borderedProminent)
+                        }
+                        .padding(24)
+                        .background(.ultraThinMaterial)
+                        .clipShape(RoundedRectangle(cornerRadius: 12))
+                    } else if store.isLoading {
                         ProgressView("加载中…")
                             .padding(20)
                             .background(.ultraThinMaterial)