Add thread drawer mode as alternative to tab layout

clients/ios/Resources/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -1,6 +1,7 @@
 {
   "images" : [
     {
+      "filename" : "AppIcon.png",
       "idiom" : "universal",
       "platform" : "ios",
       "size" : "1024x1024"

clients/ios/Resources/Info.plist

@@ -6,6 +6,8 @@
     <string>Vellum Assistant</string>
     <key>CFBundleIdentifier</key>
     <string>com.vellum.vellum-assistant-ios</string>
+    <key>CFBundleExecutable</key>
+    <string>vellum-assistant-ios</string>
     <key>CFBundleVersion</key>
     <string>1</string>
     <key>CFBundleShortVersionString</key>

clients/macos/vellum-assistant/Features/Chat/ChatView.swift

@@ -56,6 +56,7 @@ struct ChatView: View {
 
     @State private var isDropTargeted = false
     @State private var editorContentHeight: CGFloat = 20
+    @AppStorage("useThreadDrawer") private var useThreadDrawer: Bool = false
     @State private var composerScrollOffset: CGFloat = 0
 
     var body: some View {
@@ -286,7 +287,8 @@ struct ChatView: View {
                     }
                 }
                 .padding(.horizontal, VSpacing.xl)
-                .padding(.vertical, VSpacing.md)
+                .padding(.top, useThreadDrawer ? VSpacing.xs : VSpacing.md)
+                .padding(.bottom, VSpacing.md)
                 .frame(maxWidth: 700)
                 .frame(maxWidth: .infinity)
             }

clients/macos/vellum-assistant/Features/MainWindow/Panels/SettingsPanel.swift

@@ -17,6 +17,7 @@ struct SettingsPanel: View {
     @State private var hasBraveKey: Bool = false
     @AppStorage("maxStepsPerSession") private var maxSteps: Double = 50
     @AppStorage("ambientAgentEnabled") private var ambientEnabled: Bool = false
+    @AppStorage("useThreadDrawer") private var useThreadDrawer: Bool = false
 
     var body: some View {
         VSidePanel(title: "Settings", onClose: onClose) {
@@ -180,6 +181,28 @@ struct SettingsPanel: View {
                 .padding(VSpacing.lg)
                 .vCard(background: Slate._900)
 
+                // DISPLAY section
+                VStack(alignment: .leading, spacing: VSpacing.md) {
+                    Text("DISPLAY")
+                        .font(VFont.sectionTitle)
+                        .foregroundColor(VColor.textPrimary)
+
+                    HStack {
+                        VStack(alignment: .leading, spacing: VSpacing.xs) {
+                            Text("Show thread list drawer")
+                                .font(VFont.body)
+                                .foregroundColor(VColor.textSecondary)
+                            Text("Access chat history from a left-side drawer instead of tabs")
+                                .font(VFont.caption)
+                                .foregroundColor(VColor.textMuted)
+                        }
+                        Spacer()
+                        VToggle(isOn: $useThreadDrawer)
+                    }
+                }
+                .padding(VSpacing.lg)
+                .vCard(background: Slate._900)
+
                 // PERMISSIONS section
                 VStack(alignment: .leading, spacing: VSpacing.md) {
                     Text("PERMISSIONS")

clients/macos/vellum-assistant/Features/MainWindow/ThreadTab.swift

@@ -40,6 +40,8 @@ struct ThreadTab: View {
                     Image(systemName: "xmark")
                         .font(.system(size: 10, weight: .bold))
                         .foregroundColor(VColor.textMuted)
+                        .frame(width: 16, height: 16)
+                        .contentShape(Rectangle())
                 }
                 .buttonStyle(.plain)
                 .accessibilityLabel("Close \(label)")

clients/shared/DesignSystem/Components/Layout/VSplitView.swift

@@ -8,9 +8,11 @@ public struct VSplitView<Main: View, Panel: View>: View {
 
     public var body: some View {
         HStack(spacing: 0) {
+            // Main content - shrinks when panel appears
             main
                 .frame(maxWidth: .infinity, maxHeight: .infinity)
 
+            // Panel slides in from right, pushing content
             if showPanel, let panel = panel {
                 panel
                     .frame(width: panelWidth)