fix: make search bar always visible instead of toggle-behind-icon

Removed the magnifying-glass toolbar button and the isSearching state
it drove -- .searchable() now shows the search field unconditionally,
which is simpler and was requested after hands-on use showed the extra
tap added no value. Updated the spec to match.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WYqycDFsynHH9VnnK7LNSf

MyPass/Views/EntryListView.swift

@@ -4,7 +4,6 @@ import MyPassCore
 
 struct EntryListView: View {
     @ObservedObject var vm: VaultViewModel
-    @State private var isSearching = false
     @State private var showAddEntry = false
 
     var body: some View {
@@ -25,16 +24,8 @@ struct EntryListView: View {
             }
         }
         .navigationTitle("MyPass")
-        .searchable(text: $vm.searchQuery, isPresented: $isSearching, prompt: "Search entries…")
+        .searchable(text: $vm.searchQuery, prompt: "Search entries…")
         .toolbar {
-            ToolbarItem(placement: .primaryAction) {
-                Button {
-                    if isSearching { vm.searchQuery = "" }
-                    isSearching.toggle()
-                } label: {
-                    Image(systemName: "magnifyingglass")
-                }
-            }
             ToolbarItem(placement: .primaryAction) {
                 Button { showAddEntry = true } label: {
                     Image(systemName: "plus")