fix: resolve Reader freezing, article layout loop, and feedback issues

- ArticleWebView: remove dangerous intrinsicContentSize override, use
  height binding measured via JS after render
- ReaderViewModel: add @MainActor, replace didSet filter with explicit
  applyFilter() to avoid property observer reentrancy
- Thumbnail extraction: use precompiled NSRegularExpression, limit search
  to first 2000 chars, skip placeholder when no image found
- Card view: only show thumbnail when image exists (no placeholder)
- Feedback: add guard against double-tap, @MainActor on Task

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ios/Platform/Platform/Features/Feedback/FeedbackView.swift

@@ -143,10 +143,11 @@ struct FeedbackSheet: View {
     }
 
     private func sendFeedback() {
+        guard !isSending else { return }
         isSending = true
         error = nil
 
-        Task {
+        Task { @MainActor in
             do {
                 var body: [String: Any] = ["text": text.trimmingCharacters(in: .whitespaces), "source": "ios"]
                 if let imgData = photoData {

ios/Platform/Platform/Features/Reader/Models/ReaderModels.swift

@@ -49,20 +49,25 @@ struct ReaderEntry: Codable, Identifiable, Hashable {
     }
 
     var thumbnailURL: URL? {
-        // Extract first <img src="..."> from content
-        let html = content ?? fullContent ?? ""
-        guard let range = html.range(of: #"<img[^>]+src=["\']([^"\']+)["\']"#, options: .regularExpression) else {
+        ReaderEntry.extractThumbnail(from: content ?? fullContent ?? "")
+    }
+
+    private static let imgRegex = try! NSRegularExpression(
+        pattern: #"<img[^>]+src=["']([^"']+)["']"#,
+        options: .caseInsensitive
+    )
+
+    static func extractThumbnail(from html: String) -> URL? {
+        guard !html.isEmpty else { return nil }
+        // Only search first 2000 chars for performance
+        let searchRange = html.prefix(2000)
+        let nsRange = NSRange(searchRange.startIndex..., in: searchRange)
+        guard let match = imgRegex.firstMatch(in: String(searchRange), range: nsRange),
+              match.numberOfRanges > 1,
+              let srcRange = Range(match.range(at: 1), in: searchRange) else {
             return nil
         }
-        let match = String(html[range])
-        guard let srcRange = match.range(of: #"src=["\']([^"\']+)["\']"#, options: .regularExpression) else {
-            return nil
-        }
-        var src = String(match[srcRange])
-        src = src.replacingOccurrences(of: "src=\"", with: "")
-            .replacingOccurrences(of: "src='", with: "")
-            .replacingOccurrences(of: "\"", with: "")
-            .replacingOccurrences(of: "'", with: "")
+        let src = String(searchRange[srcRange])
         return URL(string: src)
     }
 

ios/Platform/Platform/Features/Reader/ViewModels/ReaderViewModel.swift

@@ -1,5 +1,6 @@
 import Foundation
 
+@MainActor
 @Observable
 final class ReaderViewModel {
     // MARK: - State
@@ -24,8 +25,11 @@ final class ReaderViewModel {
         case category(Int)
     }
 
-    var currentFilter: ReaderFilter = .unread {
-        didSet { Task { await loadEntries(reset: true) } }
+    var currentFilter: ReaderFilter = .unread
+
+    func applyFilter(_ filter: ReaderFilter) {
+        currentFilter = filter
+        Task { await loadEntries(reset: true) }
     }
 
     // MARK: - Private

ios/Platform/Platform/Features/Reader/Views/ArticleView.swift

@@ -6,6 +6,7 @@ struct ArticleView: View {
     @State private var currentEntry: ReaderEntry
     @State private var isFetchingFull = false
     @State private var savedToBrain = false
+    @State private var webViewHeight: CGFloat = 400
 
     init(entry: ReaderEntry, vm: ReaderViewModel) {
         self.entry = entry
@@ -81,8 +82,8 @@ struct ArticleView: View {
                         .padding(.vertical, 40)
                     }
                 } else {
-                    ArticleWebView(html: wrapHTML(currentEntry.articleHTML))
-                        .frame(minHeight: 400)
+                    ArticleWebView(html: wrapHTML(currentEntry.articleHTML), contentHeight: $webViewHeight)
+                        .frame(height: webViewHeight)
                 }
 
                 Spacer(minLength: 80)

ios/Platform/Platform/Features/Reader/Views/ArticleWebView.swift

@@ -3,6 +3,7 @@ import WebKit
 
 struct ArticleWebView: UIViewRepresentable {
     let html: String
+    @Binding var contentHeight: CGFloat
 
     func makeUIView(context: Context) -> WKWebView {
         let config = WKWebViewConfiguration()
@@ -18,7 +19,11 @@ struct ArticleWebView: UIViewRepresentable {
     }
 
     func updateUIView(_ webView: WKWebView, context: Context) {
-        webView.loadHTMLString(html, baseURL: nil)
+        if context.coordinator.lastHTML != html {
+            context.coordinator.lastHTML = html
+            context.coordinator.heightBinding = $contentHeight
+            webView.loadHTMLString(html, baseURL: nil)
+        }
     }
 
     func makeCoordinator() -> Coordinator {
@@ -26,12 +31,14 @@ struct ArticleWebView: UIViewRepresentable {
     }
 
     class Coordinator: NSObject, WKNavigationDelegate {
+        var lastHTML: String?
+        var heightBinding: Binding<CGFloat>?
+
         func webView(
             _ webView: WKWebView,
             decidePolicyFor navigationAction: WKNavigationAction,
             decisionHandler: @escaping (WKNavigationActionPolicy) -> Void
         ) {
-            // Allow initial HTML load, open external links in Safari
             if navigationAction.navigationType == .linkActivated,
                let url = navigationAction.request.url {
                 UIApplication.shared.open(url)
@@ -42,20 +49,16 @@ struct ArticleWebView: UIViewRepresentable {
         }
 
         func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
-            // Resize to fit content
-            webView.evaluateJavaScript("document.body.scrollHeight") { result, _ in
-                if let height = result as? CGFloat {
-                    webView.frame.size.height = height
-                    webView.invalidateIntrinsicContentSize()
+            // Measure content height after render
+            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
+                webView.evaluateJavaScript("document.body.scrollHeight") { [weak self] result, _ in
+                    if let height = result as? CGFloat, height > 0 {
+                        DispatchQueue.main.async {
+                            self?.heightBinding?.wrappedValue = height
+                        }
+                    }
                 }
             }
         }
     }
 }
-
-// Make WKWebView report intrinsic content size
-extension WKWebView {
-    override open var intrinsicContentSize: CGSize {
-        CGSize(width: UIView.noIntrinsicMetric, height: scrollView.contentSize.height)
-    }
-}

ios/Platform/Platform/Features/Reader/Views/EntryListView.swift

@@ -95,7 +95,7 @@ struct EntryCardView: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: 0) {
-            // Thumbnail
+            // Thumbnail — only show if available
             if let thumbURL = entry.thumbnailURL {
                 AsyncImage(url: thumbURL) { phase in
                     switch phase {
@@ -105,19 +105,10 @@ struct EntryCardView: View {
                             .aspectRatio(contentMode: .fill)
                             .frame(height: 180)
                             .clipped()
-                    case .failure:
-                        cardPlaceholder
-                    case .empty:
-                        ProgressView()
-                            .frame(maxWidth: .infinity)
-                            .frame(height: 180)
-                            .background(Color.accentWarm.opacity(0.06))
-                    @unknown default:
-                        cardPlaceholder
+                    default:
+                        EmptyView()
                     }
                 }
-            } else {
-                cardPlaceholder
             }
 
             // Content
@@ -182,16 +173,6 @@ struct EntryCardView: View {
         }
     }
 
-    private var cardPlaceholder: some View {
-        HStack(spacing: 8) {
-            Image(systemName: "newspaper.fill")
-                .font(.title2)
-                .foregroundStyle(Color.accentWarm.opacity(0.3))
-        }
-        .frame(maxWidth: .infinity)
-        .frame(height: 80)
-        .background(Color.accentWarm.opacity(0.06))
-    }
 }
 
 // MARK: - List Row View

ios/Platform/Platform/Features/Reader/Views/ReaderTabView.swift

@@ -17,9 +17,9 @@ struct ReaderTabView: View {
                             withAnimation(.easeInOut(duration: 0.2)) {
                                 selectedSubTab = index
                                 switch index {
-                                case 0: vm.currentFilter = .unread
-                                case 1: vm.currentFilter = .starred
-                                case 2: vm.currentFilter = .all
+                                case 0: vm.applyFilter(.unread)
+                                case 1: vm.applyFilter(.starred)
+                                case 2: vm.applyFilter(.all)
                                 default: break
                                 }
                             }
@@ -59,10 +59,10 @@ struct ReaderTabView: View {
                         feedFilterChip("All", isSelected: isAllSelected) {
                             let tab = selectedSubTab
                             switch tab {
-                            case 0: vm.currentFilter = .unread
-                            case 1: vm.currentFilter = .starred
-                            case 2: vm.currentFilter = .all
-                            default: vm.currentFilter = .unread
+                            case 0: vm.applyFilter(.unread)
+                            case 1: vm.applyFilter(.starred)
+                            case 2: vm.applyFilter(.all)
+                            default: vm.applyFilter(.unread)
                             }
                         }
 
@@ -73,7 +73,7 @@ struct ReaderTabView: View {
                                 count: selectedSubTab == 0 ? count : nil,
                                 isSelected: vm.currentFilter == .feed(feed.id)
                             ) {
-                                vm.currentFilter = .feed(feed.id)
+                                vm.applyFilter(.feed(feed.id))
                             }
                         }
                     }