fix(mac): size context bar to menu

apps/macos/Sources/Clawdis/ContextUsageBar.swift

@@ -4,7 +4,7 @@ import SwiftUI
 struct ContextUsageBar: View {
     let usedTokens: Int
     let contextTokens: Int
-    var width: CGFloat = 220
+    var width: CGFloat?
     var height: CGFloat = 6
 
     private var clampedFractionUsed: Double {
@@ -28,14 +28,30 @@ struct ContextUsageBar: View {
     var body: some View {
         // SwiftUI menus (MenuBarExtraStyle.menu) drop certain view types (including ProgressView/Canvas).
         // Render the bar as an image to reliably display inside the menu.
-        Image(nsImage: Self.renderBar(
-            width: self.width,
-            height: self.height,
-            fractionUsed: self.clampedFractionUsed,
-            percentUsed: self.percentUsed))
-            .resizable()
-            .interpolation(.none)
-            .frame(width: self.width, height: self.height)
+        Group {
+            if let width = self.width, width > 0 {
+                Image(nsImage: Self.renderBar(
+                    width: width,
+                    height: self.height,
+                    fractionUsed: self.clampedFractionUsed,
+                    percentUsed: self.percentUsed))
+                    .resizable()
+                    .interpolation(.none)
+                    .frame(width: width, height: self.height)
+            } else {
+                GeometryReader { proxy in
+                    Image(nsImage: Self.renderBar(
+                        width: proxy.size.width,
+                        height: self.height,
+                        fractionUsed: self.clampedFractionUsed,
+                        percentUsed: self.percentUsed))
+                        .resizable()
+                        .interpolation(.none)
+                        .frame(width: proxy.size.width, height: self.height)
+                }
+                .frame(height: self.height)
+            }
+        }
         .accessibilityLabel("Context usage")
         .accessibilityValue(self.accessibilityValue)
     }

apps/macos/Sources/Clawdis/MenuContentView.swift

@@ -17,6 +17,7 @@ struct MenuContent: View {
     @State private var loadingMics = false
     @State private var sessionMenu: [SessionRow] = []
     @State private var mainSessionRow: SessionRow?
+    @State private var mainSessionContextWidth: CGFloat = 0
 
     var body: some View {
         VStack(alignment: .leading, spacing: 8) {
@@ -266,9 +267,15 @@ struct MenuContent: View {
                 ContextUsageBar(
                     usedTokens: row.tokens.total,
                     contextTokens: row.tokens.contextTokens,
-                    width: 220)
+                    width: self.mainSessionContextWidth > 0 ? self.mainSessionContextWidth : nil)
             }
             .padding(.vertical, 2)
+            .onWidthChange { width in
+                let next = max(120, width)
+                if abs(next - self.mainSessionContextWidth) > 1 {
+                    self.mainSessionContextWidth = next
+                }
+            }
         } else {
             HStack(spacing: 8) {
                 Text("Context (main)")

apps/macos/Sources/Clawdis/SessionsSettings.swift

@@ -154,7 +154,7 @@ struct SessionsSettings: View {
                 ContextUsageBar(
                     usedTokens: row.tokens.total,
                     contextTokens: row.tokens.contextTokens,
-                    width: 260)
+                    width: nil)
             }
 
             HStack(spacing: 10) {

apps/macos/Sources/Clawdis/ViewMetrics.swift

@@ -0,0 +1,20 @@
+import SwiftUI
+
+private struct ViewWidthPreferenceKey: PreferenceKey {
+    static let defaultValue: CGFloat = 0
+
+    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
+        value = max(value, nextValue())
+    }
+}
+
+extension View {
+    func onWidthChange(_ onChange: @escaping (CGFloat) -> Void) -> some View {
+        self.background(
+            GeometryReader { proxy in
+                Color.clear.preference(key: ViewWidthPreferenceKey.self, value: proxy.size.width)
+            })
+            .onPreferenceChange(ViewWidthPreferenceKey.self, perform: onChange)
+    }
+}
+