diff --git a/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift b/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
index 9687246..1f77503 100644
--- a/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
+++ b/NucleicRemote/NucleicRemote/Views/SessionDetailView.swift
@@ -458,15 +458,6 @@ 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