refactor(ui): prioritize editor space

Sources/SaplingApp/SaplingApp.swift

@@ -155,16 +155,17 @@ private final class SaplingAppModel: ObservableObject {
 private struct MainWindow: View {
     @ObservedObject var model: SaplingAppModel
     @State private var isImportingMarkdown = false
+    @State private var columnVisibility: NavigationSplitViewVisibility = .all
 
     var body: some View {
-        NavigationSplitView {
+        NavigationSplitView(columnVisibility: $columnVisibility) {
             WorkspaceTreeView(
                 workspace: model.workspace,
                 onSelectFile: model.select(file:),
                 onSelectProject: model.select(project:)
             )
-            .frame(minWidth: 220)
-        } content: {
+            .navigationSplitViewColumnWidth(min: 180, ideal: 220, max: 260)
+        } detail: {
             if let editorViewModel = model.editorViewModel {
                 HybridMarkdownEditor(
                     viewModel: editorViewModel,
@@ -174,16 +175,17 @@ private struct MainWindow: View {
             } else {
                 EmptyEditorPlaceholder()
             }
-        } detail: {
-            SaplingInspectorView(
-                project: model.selectedProject,
-                document: model.editorViewModel?.document ?? model.selectedDocument,
-                statuses: model.gitStatuses
-            )
-            .frame(minWidth: 260)
         }
         .toolbar {
             ToolbarItemGroup {
+                Button {
+                    toggleSidebar()
+                } label: {
+                    Label("Toggle Sidebar", systemImage: "sidebar.leading")
+                }
+                .help("Toggle Sidebar")
+                .keyboardShortcut("0", modifiers: [.command, .option])
+
                 Button {
                     isImportingMarkdown = true
                 } label: {
@@ -232,6 +234,10 @@ private struct MainWindow: View {
     private func navigationTitle(for viewModel: HybridMarkdownEditorViewModel) -> String {
         viewModel.hasUnsavedChanges ? "\(viewModel.document.title) *" : viewModel.document.title
     }
+
+    private func toggleSidebar() {
+        columnVisibility = columnVisibility == .all ? .detailOnly : .all
+    }
 }
 
 private extension UTType {