fix: three Reader bugs — image overflow, load more, refresh read state

#22 Image overflow: added .frame(maxWidth: .infinity) before
.frame(height: 180) on AsyncImage to constrain width within card.
Card's .clipShape already clips corners.

#23 Load more not triggering: added loadMoreIfNeeded(for:) that
fires onAppear for entries 5 from the bottom. No longer relies
solely on the bottom sentinel Color.clear which could be missed.
Also increased sentinel height from 1pt to 40pt.

#24 Refresh not updating read state: flushDeferredReads() now
called before vm.refresh() in .refreshable. Deferred marks are
synced to API before re-fetching, so the server returns correct
read states. Also clears markedByScroll set.

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

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

@@ -66,6 +66,9 @@ struct EntryListView: View {
                 }
             }
             .refreshable {
+                // Flush any deferred read marks before refreshing
+                flushDeferredReads()
+                markedByScroll.removeAll()
                 await vm.refresh()
             }
             .navigationDestination(for: ReaderEntry.self) { entry in
@@ -176,6 +179,7 @@ struct EntryListView: View {
                         entryContextMenu(entry: entry, vm: vm)
                     }
                 )
+                .onAppear { loadMoreIfNeeded(for: entry) }
             }
 
             loadMoreTrigger
@@ -201,6 +205,7 @@ struct EntryListView: View {
                         entryContextMenu(entry: entry, vm: vm)
                     }
                 )
+                .onAppear { loadMoreIfNeeded(for: entry) }
 
                 Divider()
                     .padding(.leading, 36)
@@ -212,14 +217,25 @@ struct EntryListView: View {
         }
     }
 
+    // Trigger loadMore when an entry near the bottom appears
+    private func loadMoreIfNeeded(for entry: ReaderEntry) {
+        let entries = vm.entries
+        guard entries.count >= 5 else { return }
+        let threshold = entries[entries.count - 5].id
+        if entry.id == threshold {
+            Task { await vm.loadMore() }
+        }
+    }
+
     private var loadMoreTrigger: some View {
         Group {
             if vm.isLoadingMore {
                 ProgressView()
                     .padding()
-            } else {
+            } else if vm.entries.count > 0 {
+                // Fallback trigger at the very bottom
                 Color.clear
-                    .frame(height: 1)
+                    .frame(height: 40)
                     .onAppear {
                         Task { await vm.loadMore() }
                     }
@@ -242,6 +258,7 @@ struct EntryCardView: View {
                         image
                             .resizable()
                             .aspectRatio(contentMode: .fill)
+                            .frame(maxWidth: .infinity)
                             .frame(height: 180)
                             .clipped()
                     default: