Improve search field layout and responsiveness

SearchTextField improvements:
- Add flexible width constraints (minWidth: 250, maxWidth: .infinity) for macOS
- Restructure iOS layout to use HStack instead of ZStack for better alignment
- Add invisible spacer to maintain consistent width when clear button is hidden
- Adjust padding for more balanced appearance
- Remove fixed width from fieldBorder to support flexible sizing

SearchView improvements:
- Wrap in GeometryReader to calculate available width dynamically
- Add searchFieldWidth() helper to compute optimal search field width
- Account for navigation buttons and internal padding
- Apply dynamic width to both FocusableSearchTextField and SearchTextField

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Shared/Search/SearchTextField.swift

@@ -40,16 +40,15 @@ struct SearchTextField: View {
                     }
                 }
             }
+            .frame(minWidth: 250, idealWidth: 300, maxWidth: .infinity)
             .transaction { t in t.animation = nil }
         }
     #else
         var body: some View {
-            ZStack {
-                HStack {
             HStack(spacing: 0) {
                 Image(systemName: "magnifyingglass")
                     .foregroundColor(.gray)
-                            .padding(.leading, 5)
+                    .padding(.leading, 8)
                     .padding(.trailing, 5)
                     .imageScale(.medium)
 
@@ -67,7 +66,13 @@ struct SearchTextField: View {
                 if !state.queryText.isEmpty {
                     clearButton
                         .padding(.leading, 5)
-                                .padding(.trailing, 5)
+                        .padding(.trailing, 8)
+                } else {
+                    // Invisible spacer to maintain consistent width
+                    clearButton
+                        .opacity(0)
+                        .padding(.leading, 5)
+                        .padding(.trailing, 8)
                 }
             }
             .background(
@@ -78,10 +83,7 @@ struct SearchTextField: View {
                 RoundedRectangle(cornerRadius: 8)
                     .stroke(Color(UIColor.secondarySystemBackground), lineWidth: 1)
             )
-                    .frame(maxWidth: .infinity, alignment: .leading)
+            .padding(.horizontal, 16)
-                }
-                .padding(.horizontal, 0)
-            }
             .transaction { t in t.animation = nil }
         }
     #endif
@@ -89,11 +91,11 @@ struct SearchTextField: View {
     private var fieldBorder: some View {
         RoundedRectangle(cornerRadius: 5, style: .continuous)
             .fill(Color.background)
-            .frame(width: 250, height: 27)
+            .frame(height: 27)
             .overlay(
                 RoundedRectangle(cornerRadius: 5, style: .continuous)
                     .stroke(Color.gray.opacity(0.4), lineWidth: 1)
-                    .frame(width: 250, height: 27)
+                    .frame(height: 27)
             )
     }
 

Shared/Search/SearchView.swift

@@ -41,6 +41,7 @@ struct SearchView: View {
 
     #if os(iOS)
         var body: some View {
+            GeometryReader { geometry in
                 VStack {
                     VStack {
                         if accounts.app.supportsSearchSuggestions, state.query.query != state.queryText {
@@ -58,14 +59,17 @@ struct SearchView: View {
                     ToolbarItem(placement: .principal) {
                         if #available(iOS 15, *) {
                             FocusableSearchTextField()
+                                .frame(width: searchFieldWidth(geometry.size.width))
                         } else {
                             SearchTextField()
+                                .frame(width: searchFieldWidth(geometry.size.width))
                         }
                     }
                     ToolbarItem(placement: .navigationBarTrailing) {
                         searchMenu
                     }
                 }
+            }
             .navigationBarTitleDisplayMode(.inline)
             .ignoresSafeArea(.keyboard, edges: .bottom)
             .navigationTitle("Search")
@@ -645,6 +649,26 @@ struct SearchView: View {
         ))
     }
 
+    #if os(iOS)
+    private func searchFieldWidth(_ viewWidth: CGFloat) -> CGFloat {
+        // Base padding for internal SearchTextField padding (16pt each side = 32 total)
+        var totalDeduction: CGFloat = 32
+        
+        // Add space for trailing menu button
+        totalDeduction += 44
+        
+        // Add space for sidebar toggle button if in sidebar navigation style
+        if navigationStyle == .sidebar {
+            totalDeduction += 44
+        }
+        
+        // Minimum width to ensure usability
+        let minWidth: CGFloat = 200
+        
+        return max(minWidth, viewWidth - totalDeduction)
+    }
+    #endif
+
     var shouldDisplayHeader: Bool {
         #if os(tvOS)
             !state.query.isEmpty