nvrsion: Add: Investigate Live Activity Session Load logic in SessionDetailView.swift and investigate why Live Activity Session Load doesn’t always trigger when a session is opened; add Stop Button Implementation in iOS app’s composer.

Nucleic-Promote: 1
Co-authored-by: Nucleic <[email protected]>

NucleicRemote/NucleicRemote/Views/SessionDetailView.swift

@@ -31,18 +31,20 @@ struct SessionDetailView: View {
     }
 
     var body: some View {
+        // The detail's height comes from the enclosing GeometryReader — a value fixed by the parent
+        // (the navigation content area), never by anything inside it. The attention cards (approval /
+        // question) cap themselves to this so their buttons stay on-screen. Sourcing it from a
+        // GeometryReader — rather than measuring the transcript, whose height the cards' own bottom
+        // `safeAreaInset` resizes — makes the measurement categorically independent of the card, so
+        // the card can't feed its height back into the value it's sized from. That feedback was an
+        // unresolved layout cycle that pinned the main thread at 100% CPU during the push transition;
+        // it showed up intermittently because a feedback loop only diverges for some content/card-
+        // height combinations. It bit only the attention path (a card consumes this value; the plain
+        // composer doesn't), which is why a "Working" tap opened fine and an "attention" tap hung.
+        GeometryReader { proxy in
             TranscriptList(events: store.openEvents,
                            scrollToBottomRequest: scrollToBottomRequest,
                            isScrolledToBottom: $isScrolledToBottom)
-            // Measure the transcript's full height (the floating bar overlays it via safeAreaInset,
-            // so this frame is the whole screen area the card has to live within) and hand it to the
-            // action card so it can bound itself.
-            .background {
-                GeometryReader { proxy in
-                    Color.clear.preference(key: AvailableHeightKey.self, value: proxy.size.height)
-                }
-            }
-            .onPreferenceChange(AvailableHeightKey.self) { availableHeight = $0 }
                 // The chat bar floats over the scrolling content on Liquid Glass instead of sitting
                 // in a boxed strip below it, so the transcript runs the full height of the screen.
                 .safeAreaInset(edge: .bottom) { actionArea }
@@ -81,6 +83,14 @@ struct SessionDetailView: View {
                 // disappears) unsubscribes A without tearing down B's just-opened state.
                 .onDisappear { store.closeOpen(sessionID) }
                 .background { interruptShortcut }
+                // Publish the parent-determined height to the cards. `initial: true` seeds it on the
+                // first layout; it refreshes if the container resizes (rotation, keyboard, iPad split
+                // resize). Because `proxy.size.height` never depends on the card, updating this can't
+                // re-drive the measurement — no cycle.
+                .onChange(of: proxy.size.height, initial: true) { _, height in
+                    availableHeight = height
+                }
+        }
     }
 
     /// ⌘. interrupts a running session (the Mac's "stop" convention) — the action is otherwise
@@ -352,6 +362,18 @@ struct SessionDetailView: View {
                                     .textFieldStyle(.plain)
                                     .lineLimit(1...4)
                                     .padding(.vertical, 3)
+                                // Stop the in-flight turn (the Mac's ⌘. / "Interrupt"). Shown only
+                                // while running and at control scope; send stays at the far right so
+                                // its position never shifts. Mirrors `interruptShortcut`.
+                                if running && store.canControl {
+                                    Button { store.interrupt(sessionID) } label: {
+                                        Image(systemName: "stop.circle.fill")
+                                            .font(.title2)
+                                            .foregroundStyle(.red)
+                                    }
+                                    .disabled(!store.connectivity.isLive)
+                                    .accessibilityLabel("Stop")
+                                }
                                 Button {
                                     store.sendInput(draft, to: sessionID)
                                     draft = ""
@@ -448,15 +470,6 @@ struct SessionDetailView: View {
     }
 }
 
-/// The transcript's measured height, fed to the floating action card so it can bound itself to the
-/// screen (see `availableHeight`).
-private struct AvailableHeightKey: PreferenceKey {
-    static var defaultValue: CGFloat { 0 }
-    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
-        value = max(value, nextValue())
-    }
-}
-
 struct TranscriptList: View {
     let events: [AgentEvent]
     /// Bumped by the parent when the user sends a message — a deliberate "show me what happens