feat: read-shelf auto-expand, stripe removal, pull-reshuffle, BG notifications

- Mark-read now immediately expands the READ shelf so the story is visible
- Orange signal stripe is fully removed (not dimmed) when isRead=true
- Pull-to-refresh clears seen snapshot → full reshuffle by signal score
- BackgroundRefreshManager fires a local notification for the top new
  high-signal story after each cache refresh; Tech/AI/HomeLab stories
  get their category in the notification title (≥65 signal threshold)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Jarvis/Views/Home/StoryRowView.swift

@@ -41,7 +41,12 @@ struct StoryRowView: View {
 
     private var fullBody: some View {
         HStack(alignment: .top, spacing: 0) {
-            SignalStripe(score: story.signalScore, muted: isRead)
+            if isRead {
+                // No stripe for read stories — remove the orange signal indicator entirely.
+                Color.clear.frame(width: 3)
+            } else {
+                SignalStripe(score: story.signalScore)
+            }
 
             VStack(alignment: .leading, spacing: 9) {
                 // Title (+ cached dot)
@@ -90,7 +95,6 @@ struct StoryRowView: View {
                 .padding(.trailing, 16)
                 .padding(.top, 16)
         }
-        .opacity(isRead ? 0.55 : 1)
         .frame(maxWidth: .infinity, alignment: .leading)
         .background(Color.black)
         .overlay(alignment: .bottom) {