fix: Reader pre-loads on app launch, no more glitchy initial state

- ReaderViewModel starts with isLoading=true (shows spinner, not "No articles")
- MainTabView owns ReaderViewModel and pre-fetches in background on launch
- Sub-tabs and feed chips hidden during initial load (no tiny squished layout)
- VStack fills full screen with frame(maxWidth/maxHeight: .infinity)
- WebKit warmer triggers when Reader tab appears
- By the time user taps Reader, data is already loaded

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

ios/Platform/Platform/ContentView.swift

@@ -26,6 +26,7 @@ struct MainTabView: View {
     @State private var selectedTab = 0
     @State private var showAssistant = false
     @State private var confettiTrigger = 0
+    @State private var readerVM = ReaderViewModel()
 
     var body: some View {
         ZStack {
@@ -38,12 +39,16 @@ struct MainTabView: View {
                     .tabItem { Label("Fitness", systemImage: "flame.fill") }
                     .tag(1)
 
-                ReaderTabView()
+                ReaderTabView(vm: readerVM)
                     .tabItem { Label("Reader", systemImage: "newspaper.fill") }
                     .tag(2)
             }
             .tint(Color.accentWarm)
             .modifier(TabBarMinimizeModifier())
+            .task {
+                // Pre-fetch reader data in background while user is on Home/Fitness
+                await readerVM.loadInitial()
+            }
 
             // Floating buttons
             VStack {

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

@@ -10,7 +10,7 @@ final class ReaderViewModel {
     var categories: [ReaderCategory] = []
     var counters: ReaderCounters?
     var total = 0
-    var isLoading = false
+    var isLoading = true
     var isLoadingMore = false
     var isRefreshing = false
     var error: String?

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

@@ -1,7 +1,7 @@
 import SwiftUI
 
 struct ReaderTabView: View {
-    @State private var vm = ReaderViewModel()
+    @Bindable var vm: ReaderViewModel
     @State private var selectedSubTab = 0
     @State private var showFeedSheet = false
     @State private var showFeedManagement = false
@@ -10,7 +10,8 @@ struct ReaderTabView: View {
     var body: some View {
         NavigationStack {
             VStack(spacing: 0) {
-                // Sub-tab selector
+                if !vm.isLoading || !vm.entries.isEmpty {
+                    // Sub-tab selector — only show after initial load
                     HStack(spacing: 0) {
                         ForEach(Array(subTabs.enumerated()), id: \.offset) { index, tab in
                             Button {
@@ -54,6 +55,7 @@ struct ReaderTabView: View {
                     .padding(.top, 8)
 
                     // Feed filter bar
+                    if !vm.feeds.isEmpty {
                         ScrollView(.horizontal, showsIndicators: false) {
                             HStack(spacing: 8) {
                                 feedFilterChip("All", isSelected: isAllSelected) {
@@ -80,10 +82,13 @@ struct ReaderTabView: View {
                             .padding(.horizontal)
                             .padding(.vertical, 8)
                         }
+                    }
+                }
 
-                // Entry list
+                // Entry list (shows LoadingView when isLoading)
                 EntryListView(vm: vm, isCardView: isCardView)
             }
+            .frame(maxWidth: .infinity, maxHeight: .infinity)
             .background(Color.canvas)
             .navigationBarHidden(true)
             .toolbar {
@@ -137,9 +142,8 @@ struct ReaderTabView: View {
                 FeedManagementSheet(vm: vm)
             }
         }
-        .task {
+        .onAppear {
             WebKitWarmer.shared.warmUp()
-            await vm.loadInitial()
         }
     }