fix: speed pill and feedback in same VStack — no more guessing position

Speed pill and feedback button were in separate VStacks with
independent absolute padding, causing misalignment. Now they share
one VStack with .padding(.bottom, 70) at the container level.
The speed pill sits directly above the tab bar area, positioned
relative to the same anchor as all other bottom controls.

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

ios/Platform/Platform/ContentView.swift

@@ -73,23 +73,12 @@ struct MainTabView: View {
             .tint(Color.accentWarm)
             .tabBarMinimizeBehavior(.onScrollDown)
 
-            // Feedback button (not on Reader)
-            if selectedTab != 2 {
-                VStack {
-                    Spacer()
-                    HStack {
-                        FeedbackButton()
-                            .padding(.leading, 20)
-                        Spacer()
-                    }
-                    .padding(.bottom, 70)
-                }
-            }
+            // Bottom floating controls
+            VStack(spacing: 10) {
+                Spacer()
 
-            // Auto-scroll speed controls (overlay when playing on Reader)
-            if isAutoScrolling && selectedTab == 2 {
-                VStack {
-                    Spacer()
+                // Speed pill (only when auto-scrolling on Reader)
+                if isAutoScrolling && selectedTab == 2 {
                     HStack(spacing: 12) {
                         Button {
                             scrollSpeed = max(0.25, scrollSpeed - 0.25)
@@ -117,11 +106,20 @@ struct MainTabView: View {
                     .padding(.vertical, 10)
                     .background(.regularMaterial, in: Capsule())
                     .shadow(color: .black.opacity(0.15), radius: 12, y: 4)
-                    .padding(.bottom, 50)
                     .transition(.move(edge: .bottom).combined(with: .opacity))
                 }
-                .animation(.spring(duration: 0.3), value: isAutoScrolling)
+
+                // Feedback button (not on Reader)
+                if selectedTab != 2 {
+                    HStack {
+                        FeedbackButton()
+                            .padding(.leading, 20)
+                        Spacer()
+                    }
+                }
             }
+            .padding(.bottom, 70)
+            .animation(.spring(duration: 0.3), value: isAutoScrolling)
         }
         .confettiCannon(
             trigger: $confettiTrigger,