ios: smooth Agent entrances and refresh app icon

Grow row height and spacing with the existing entrance animation, remove the Latest overlay while retaining scroll/read/send behavior, and reuse the current PWA icon artwork. Cover occupied-height interpolation and scroll-to-latest navigation in focused checks.

ios/Packages/Sybil/Sources/Sybil/SybilAgentView.swift

@@ -44,7 +44,7 @@ private struct AgentTranscriptView: View {
         let displayed = transcript.displayed
         ScrollViewReader { proxy in
             ScrollView {
-                LazyVStack(alignment: .leading, spacing: 15) {
+                LazyVStack(alignment: .leading, spacing: 0) {
                     // The native scroll origin is the visual bottom. Keep model
                     // and cursor order ascending; reverse only presentation.
                     Color.clear.frame(height: 17).id(Self.bottomID)
@@ -56,18 +56,22 @@ private struct AgentTranscriptView: View {
                         }
                         .foregroundStyle(SybilTheme.textMuted)
                         .accessibilityIdentifier("agent-typing")
+                        .padding(.bottom, 15)
                         .scaleEffect(x: 1, y: -1)
                     }
                     ForEach(Array(displayed.enumerated().reversed()), id: \.element.id) { index, message in
                         AgentTranscriptRow(message: message, room: room,
                             startsDay: index == 0 || !Calendar.current.isDate(message.createdAt, inSameDayAs: displayed[index - 1].createdAt))
                             .equatable()
+                            // Include the gap in the occupied-space entrance.
+                            .padding(.bottom, 15)
                             .modifier(AgentEntrance(animate: appeared && rendered.entranceIDs.contains(message.id), reduceMotion: reduceMotion))
                             .scaleEffect(x: 1, y: -1)
                             .id(message.id)
                     }
                     if room.isLoading {
                         ProgressView("Loading messages…").frame(maxWidth: .infinity)
+                            .padding(.bottom, 15)
                             .scaleEffect(x: 1, y: -1)
                     }
                     if allMessages.count > displayed.count {
@@ -78,6 +82,7 @@ private struct AgentTranscriptView: View {
                         }
                         .frame(maxWidth: .infinity)
                         .padding(.vertical, 10)
+                        .padding(.bottom, 15)
                         .scaleEffect(x: 1, y: -1)
                     }
                 }
@@ -104,28 +109,12 @@ private struct AgentTranscriptView: View {
                 AgentRenderDiagnostics.record("scrollGeometry")
                 #endif
                 scrollTracking.atBottom = atBottom
-                // Only user scrolling changes follow intent. Animated Latest
-                // navigation and native keyboard resizing must not cancel it.
+                // Only user scrolling changes follow intent. Send navigation
+                // and native keyboard resizing must not cancel it.
                 if isScrolling && scrollPhase != .animating {
                     atLatest = atBottom
                 }
             }
-            .overlay(alignment: .bottomTrailing) {
-                if !atLatest {
-                    Button {
-                        atLatest = true
-                        withAnimation(reduceMotion ? nil : .easeOut(duration: 0.24)) { proxy.scrollTo(Self.bottomID, anchor: .top) }
-                    } label: {
-                        Label(room.unreadCount > 0 ? "\(room.unreadCount) unread" : "Latest", systemImage: "arrow.down")
-                            .font(.sybil(.caption, weight: .semibold))
-                            .padding(12)
-                            .background(SybilTheme.surfaceStrong, in: Capsule())
-                            .overlay(Capsule().stroke(SybilTheme.border))
-                    }
-                    .padding(14)
-                    .accessibilityIdentifier("agent-jump-latest")
-                }
-            }
             .onAppear {
                 appeared = true
                 if !room.isLoading {
@@ -306,17 +295,37 @@ private struct AgentMessageRow: View {
     }
 }
 
-// Keep the row's measured height stable for lazy layout. Animate its appearance
-// without collapsing the scroll target while the composer or keyboard resizes.
+// Grow the occupied space with the bubble's entrance so neighboring rows move
+// smoothly. Measure at natural height; no geometry state or scroll correction.
+private struct AgentEntranceLayout: Layout {
+    var progress: CGFloat
+    var animatableData: CGFloat {
+        get { progress }
+        set { progress = newValue }
+    }
+
+    func sizeThatFits(proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) -> CGSize {
+        let size = subviews.first?.sizeThatFits(.init(width: proposal.width, height: nil)) ?? .zero
+        return CGSize(width: size.width, height: size.height * progress)
+    }
+
+    func placeSubviews(in bounds: CGRect, proposal: ProposedViewSize, subviews: Subviews, cache: inout ()) {
+        subviews.first?.place(at: bounds.origin, proposal: .init(width: bounds.width, height: nil))
+    }
+}
+
 private struct AgentEntrance: ViewModifier {
     var animate: Bool
     var reduceMotion: Bool
     @State private var entered = false
     func body(content: Content) -> some View {
         let preparing = animate && !entered && !reduceMotion
-        content
-        .opacity(preparing ? 0 : 1)
-        .offset(y: preparing ? 16 : 0)
+        AgentEntranceLayout(progress: preparing ? 0 : 1) {
+            content
+                .opacity(preparing ? 0 : 1)
+                .offset(y: preparing ? 16 : 0)
+        }
+        .clipped()
         .onAppear {
             withAnimation(animate && !reduceMotion ? .easeOut(duration: 0.24) : nil) { entered = true }
         }