fix: hide FAB on Reader tab, fix tab bar collapse during auto-scroll, position glass bar bottom-right

1. FAB hidden when selectedTab == 2 (Reader) — no plus button
   on Reader since it's for food logging

2. Auto-scroll now notifies original UIScrollViewDelegate via
   scrollViewDidScroll after each contentOffset change — this
   triggers tabBarMinimizeBehavior so the tab bar collapses
   during auto-scroll just like manual scrolling

3. Glass control bar positioned bottom-right (like Photos search
   icon) instead of bottom-center

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

ios/Platform/Platform/ContentView.swift

@@ -53,17 +53,16 @@ struct MainTabView: View {
             .tint(Color.accentWarm)
             .modifier(TabBarMinimizeModifier())
 
-            // Floating buttons
+            // Floating buttons (hidden on Reader tab)
+            if selectedTab != 2 {
                 VStack {
                     Spacer()
                     HStack(alignment: .bottom) {
-                    // Feedback button (subtle, bottom-left)
                         FeedbackButton()
                             .padding(.leading, 20)
 
                         Spacer()
 
-                    // Add food button (prominent, bottom-right)
                         Button { showAssistant = true } label: {
                             Image(systemName: "plus")
                                 .font(.title2.weight(.semibold))
@@ -78,6 +77,7 @@ struct MainTabView: View {
                     .padding(.bottom, 70)
                 }
             }
+        }
         .confettiCannon(
             trigger: $confettiTrigger,
             num: 80,

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

@@ -11,7 +11,7 @@ struct ReaderTabView: View {
 
     var body: some View {
         NavigationStack {
-            ZStack(alignment: .bottom) {
+            ZStack(alignment: .bottomTrailing) {
                 VStack(spacing: 0) {
                     // Sub-tab selector
                     HStack(spacing: 0) {
@@ -93,7 +93,8 @@ struct ReaderTabView: View {
 
                 // MARK: - Liquid Glass Control Bar
                 glassControlBar
-                    .padding(.bottom, 2)
+                    .padding(.trailing, 16)
+                    .padding(.bottom, 4)
             }
             .navigationBarHidden(true)
             .sheet(isPresented: $showFeedSheet) {

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

@@ -110,6 +110,9 @@ struct ScrollViewDriver: UIViewRepresentable {
 
             sv.contentOffset.y = newY
 
+            // Notify delegate so tab bar minimize behavior triggers
+            originalDelegate?.scrollViewDidScroll?(sv)
+
             // Stop at bottom
             if newY >= maxOffset - 1 {
                 stopAndNotify()