Merge nucleic/trunk into dev (resolve promotion conflict)

NucleicRemote/NucleicRemote/Views/SessionDetailView.swift

@@ -27,6 +27,10 @@ struct SessionDetailView: View {
             .safeAreaInset(edge: .bottom) { actionArea }
             .navigationTitle(summary?.title ?? "Session")
             .navigationBarTitleDisplayMode(.inline)
+            // With a session open the floating chat bar owns the bottom edge; the tab bar below it
+            // would be a redundant second bar (and clip the glass action area), so hide it while
+            // this detail is pushed. A no-op in the iPad split, which has no tab bar.
+            .toolbar(.hidden, for: .tabBar)
             .toolbar {
                 ToolbarItem(placement: .topBarTrailing) { sessionMenu }
             }

NucleicRemote/NucleicRemote/Views/SessionsView.swift

@@ -108,28 +108,31 @@ struct SessionsView: View {
                         }
                     }
                 }
-                .presentationDetents([.medium, .large])
+                // The composer needs only a fraction of the screen — a compact height by default,
+                // still expandable if the advanced options are opened.
+                .presentationDetents([.height(360), .large])
+                .presentationDragIndicator(.visible)
             }
             .safeAreaInset(edge: .bottom) { ConnectionChip().padding(.bottom, 8) }
         }
     }
 
-    /// The circular plus button, styled to match the transcript's jump-to-bottom FAB: an accent
+    /// The circular plus button, on Liquid Glass rather than a solid teal disc — an accent-tinted
-    /// disc with a soft shadow, floated clear of the connection chip.
+    /// glyph over a translucent glass circle so it reads as a floating control, not a stamped
+    /// button. Sits low over the list, clear of the connection chip.
     private var newChatButton: some View {
         Button {
             showNewChat = true
         } label: {
             Image(systemName: "plus")
                 .font(.system(size: 22, weight: .semibold))
-                .foregroundStyle(.white)
+                .foregroundStyle(Palette.accent)
                 .frame(width: 56, height: 56)
-                .background(Palette.accent, in: .circle)
+                .glassCircle()
-                .shadow(color: .black.opacity(0.25), radius: 6, y: 2)
         }
         .buttonStyle(.plain)
         .padding(.trailing, 20)
-        .padding(.bottom, 20)
+        .padding(.bottom, 6)
         .accessibilityLabel("New chat")
     }
 

NucleicRemote/NucleicRemote/Views/Theme.swift

@@ -354,6 +354,22 @@ struct GlassSurface: ViewModifier {
     }
 }
 
+/// A circular Liquid Glass backing for a floating round control (the New-chat FAB). Real
+/// interactive `glassEffect` on iOS 26; an ultra-thin material disc with a hairline edge and a
+/// soft shadow on earlier systems so it still lifts off the list.
+struct GlassCircle: ViewModifier {
+    func body(content: Content) -> some View {
+        if #available(iOS 26.0, *) {
+            content.glassEffect(.regular.interactive(), in: .circle)
+        } else {
+            content
+                .background(.ultraThinMaterial, in: .circle)
+                .overlay(Circle().strokeBorder(Color.primary.opacity(0.08), lineWidth: 1))
+                .shadow(color: .black.opacity(0.2), radius: 6, y: 2)
+        }
+    }
+}
+
 /// A lifted card surface with a hairline border — the mobile echo of `AppTheme.surface`.
 struct CardBackground: ViewModifier {
     var padding: CGFloat = 14
@@ -373,6 +389,9 @@ extension View {
     func glassSurface(cornerRadius: CGFloat = 24) -> some View {
         modifier(GlassSurface(cornerRadius: cornerRadius))
     }
+    /// Back a circular control (the floating New-chat FAB) with interactive Liquid Glass — the
+    /// round analogue of `glassSurface`, falling back to an ultra-thin material disc pre-iOS 26.
+    func glassCircle() -> some View { modifier(GlassCircle()) }
     /// Apply the teal accent app-wide.
     func nucleicTint() -> some View { tint(Palette.accent) }
     /// Give a text field a way to release the keyboard. Without this, iOS leaves a focused