Add swipe actions: left to save, right to share + mark read

- Swipe left bookmarks a story (toggle) into the Saved tab; swipe right opens
  the iOS share sheet and marks the story read.
- New SavedStory SwiftData model; Saved tab now lists explicit bookmarks
  instead of the whole offline cache.
- Convert the feed to a styled List (native swipeActions require it), keeping
  the flat look, pull-to-refresh, and infinite scroll. Add a ShareSheet wrapper.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Jarvis/Views/Home/SignalFeedView.swift

@@ -24,13 +24,16 @@ struct SignalFeedView: View {
     @Query private var cachedStories: [CachedStory]
     @Query private var cachedArticles: [CachedArticle]
     @Query private var readStories: [ReadStory]
+    @Query private var savedStories: [SavedStory]
     @State private var showFeeds = false
     @State private var showSettings = false
     @State private var selectedInterest: Interest? = nil
+    @State private var shareStory: StorySummary?
 
     /// Stories that have full article content cached → eligible for the green dot.
     private var cachedStoryIds: Set<String> { Set(cachedArticles.map(\.storyId)) }
     private var readStoryIds: Set<String> { Set(readStories.map(\.id)) }
+    private var savedStoryIds: Set<String> { Set(savedStories.map(\.id)) }
 
     /// Live stories when online; cached fallback when the feed is empty & offline.
     private var displayStories: [StorySummary] {
@@ -81,6 +84,9 @@ struct SignalFeedView: View {
             .sheet(isPresented: $showSettings) {
                 SettingsView()
             }
+            .sheet(item: $shareStory) { story in
+                ShareSheet(items: shareItems(story))
+            }
         }
         .preferredColorScheme(.dark)
         .onChange(of: store.stories) { _, newValue in
@@ -195,33 +201,60 @@ struct SignalFeedView: View {
     // MARK: - Feed list
 
     private var feedList: some View {
-        ScrollView {
-            LazyVStack(spacing: 0) {
-                if displayStories.isEmpty {
-                    emptyState
-                } else {
-                    ForEach(displayStories) { story in
-                        NavigationLink(value: story) {
-                            StoryRowView(story: story,
-                                         isCached: cachedStoryIds.contains(story.id),
-                                         isRead: readStoryIds.contains(story.id))
-                        }
-                        .buttonStyle(.plain)
-                        .onAppear {
-                            if story.id == displayStories.last?.id {
-                                Task { await store.loadMore() }
-                            }
+        List {
+            if displayStories.isEmpty {
+                emptyState
+                    .listRowInsets(EdgeInsets())
+                    .listRowBackground(Color.black)
+                    .listRowSeparator(.hidden)
+            } else {
+                ForEach(displayStories) { story in
+                    NavigationLink(value: story) {
+                        StoryRowView(story: story,
+                                     isCached: cachedStoryIds.contains(story.id),
+                                     isRead: readStoryIds.contains(story.id))
+                    }
+                    .listRowInsets(EdgeInsets())
+                    .listRowBackground(Color.black)
+                    .listRowSeparator(.hidden)
+                    .onAppear {
+                        if story.id == displayStories.last?.id {
+                            Task { await store.loadMore() }
                         }
                     }
+                    // Swipe left → Save · swipe right → Share + mark read
+                    .swipeActions(edge: .trailing, allowsFullSwipe: true) {
+                        Button { toggleSave(story) } label: {
+                            Label(isSaved(story) ? "Saved" : "Save",
+                                  systemImage: isSaved(story) ? "bookmark.fill" : "bookmark")
+                        }
+                        .tint(Palette.healthActive)
+                    }
+                    .swipeActions(edge: .leading, allowsFullSwipe: true) {
+                        Button {
+                            markRead(story)
+                            shareStory = story
+                        } label: {
+                            Label("Share", systemImage: "square.and.arrow.up")
+                        }
+                        .tint(Palette.orange)
+                    }
+                }
 
-                    if store.isLoadingMore {
-                        ProgressView()
-                            .tint(Palette.orange)
-                            .padding(.vertical, 20)
-                    }
+                if store.isLoadingMore {
+                    ProgressView()
+                        .tint(Palette.orange)
+                        .frame(maxWidth: .infinity)
+                        .padding(.vertical, 20)
+                        .listRowInsets(EdgeInsets())
+                        .listRowBackground(Color.black)
+                        .listRowSeparator(.hidden)
                 }
             }
         }
+        .listStyle(.plain)
+        .scrollContentBackground(.hidden)
+        .background(Color.black)
         .refreshable {
             await store.loadStories(refresh: true)
         }
@@ -303,6 +336,41 @@ struct SignalFeedView: View {
         .padding(.top, 6)
     }
 
+    // MARK: - Swipe actions
+
+    private func isSaved(_ s: StorySummary) -> Bool { savedStoryIds.contains(s.id) }
+
+    /// Swipe left → toggle Save (bookmarks the story to the Saved tab).
+    private func toggleSave(_ s: StorySummary) {
+        let id = s.id
+        if let row = (try? modelContext.fetch(
+            FetchDescriptor<SavedStory>(predicate: #Predicate { $0.id == id })))?.first {
+            modelContext.delete(row)
+        } else {
+            cacheStories([s])               // keep metadata so it renders in Saved
+            modelContext.insert(SavedStory(id: id))
+        }
+        try? modelContext.save()
+    }
+
+    private func markRead(_ s: StorySummary) {
+        let id = s.id
+        let existing = try? modelContext.fetch(
+            FetchDescriptor<ReadStory>(predicate: #Predicate { $0.id == id }))
+        if existing?.first == nil {
+            modelContext.insert(ReadStory(id: id))
+            try? modelContext.save()
+        }
+    }
+
+    private func shareItems(_ s: StorySummary) -> [Any] {
+        var items: [Any] = ["\(s.headline)\n\n\(s.summary)\n\nvia Jarvis"]
+        if let first = s.sources.first, let url = URL(string: first.url) {
+            items.append(url)
+        }
+        return items
+    }
+
     // MARK: - Caching
 
     private func cacheStories(_ stories: [StorySummary]) {