diff --git a/pubspec.yaml b/pubspec.yaml
index 63e0c82b..4d2ed61a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -18,7 +18,7 @@ repository: https://github.com/postmeridiem/clide
 
 # Pre-push line-coverage floor. Ratchets up only — see D-66.
 # Reading: `awk -F: '/^coverage_floor:/ {gsub(/ /,"",$2); print $2}' pubspec.yaml`.
-coverage_floor: 83
+coverage_floor: 86
 
 # Project metadata (was project.yaml, folded in per D-056).
 # version: above is the single source of truth. The Makefile reads
diff --git a/test/widgets/zero_coverage_widgets_test.dart b/test/widgets/zero_coverage_widgets_test.dart
new file mode 100644
index 00000000..7a92bbef
--- /dev/null
+++ b/test/widgets/zero_coverage_widgets_test.dart
@@ -0,0 +1,256 @@
+/// Smoke + branch tests for the previously-uncovered widgets under
+/// `lib/widgets/src/`: ClidePalette, ClideFilterBox, ColumnHat,
+/// ClideIconRail, ClideSpine, ClideResizeBorder.
+library;
+
+import 'package:clide/clide.dart';
+import 'package:clide/extension/extension.dart';
+import 'package:clide/widgets/src/clide_column_hat.dart';
+import 'package:clide/widgets/src/clide_filter_box.dart';
+import 'package:clide/widgets/src/clide_icon_rail.dart';
+import 'package:clide/widgets/src/clide_palette.dart';
+import 'package:clide/widgets/src/clide_resize_border.dart';
+import 'package:clide/widgets/src/clide_spine.dart';
+import 'package:clide/widgets/src/icons/phosphor.dart';
+import 'package:clide/kernel/kernel.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../helpers/kernel_fixture.dart';
+import '../helpers/widget_harness.dart';
+
+void main() {
+  group('ClidePalette', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('renders nothing when the palette is closed', (tester) async {
+      await tester.pumpWidget(harness(f, Stack(children: const [ClidePalette()])));
+      expect(find.byType(EditableText), findsNothing);
+    });
+
+    testWidgets('opens to show an input field + the registered commands', (tester) async {
+      f.services.commands.register(CommandContribution(
+        id: 'c1',
+        command: 'cmd.one',
+        title: 'Command One',
+        defaultBinding: 'ctrl+1',
+        run: (_) async => IpcResponse.ok(id: '', data: const {}),
+      ));
+      f.services.commands.register(CommandContribution(
+        id: 'c2',
+        command: 'cmd.two',
+        title: 'Command Two',
+        run: (_) async => IpcResponse.ok(id: '', data: const {}),
+      ));
+      f.services.palette.open();
+      await tester.pumpWidget(harness(f, Stack(children: const [ClidePalette()])));
+      await tester.pumpAndSettle();
+      expect(find.byType(EditableText), findsOneWidget);
+      expect(find.text('Command One'), findsOneWidget);
+      expect(find.text('Command Two'), findsOneWidget);
+    });
+
+    testWidgets('tapping a row invokes the command + closes the palette', (tester) async {
+      var invocations = 0;
+      f.services.commands.register(CommandContribution(
+        id: 'c1',
+        command: 'tap.target',
+        title: 'Tap Target',
+        run: (_) async {
+          invocations++;
+          return IpcResponse.ok(id: '', data: const {});
+        },
+      ));
+      f.services.palette.open();
+      await tester.pumpWidget(harness(f, Stack(children: const [ClidePalette()])));
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('Tap Target'));
+      await tester.pumpAndSettle();
+      expect(invocations, 1);
+    });
+  });
+
+  group('ClideFilterBox', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('debounces onChanged calls to the configured duration', (tester) async {
+      final values = <String>[];
+      await tester.pumpWidget(harness(
+        f,
+        ClideFilterBox(
+          onChanged: values.add,
+          debounce: const Duration(milliseconds: 50),
+        ),
+      ));
+      // Type into the editable text field.
+      await tester.enterText(find.byType(EditableText), 'abc');
+      // Before the debounce elapses no call.
+      await tester.pump(const Duration(milliseconds: 10));
+      expect(values, isEmpty);
+      // After it fires we get exactly one call with the final value.
+      await tester.pump(const Duration(milliseconds: 100));
+      expect(values, ['abc']);
+    });
+
+    testWidgets('clear button appears once the field has text and resets onChanged when tapped', (tester) async {
+      final values = <String>[];
+      await tester.pumpWidget(harness(
+        f,
+        ClideFilterBox(
+          onChanged: values.add,
+          debounce: const Duration(milliseconds: 10),
+        ),
+      ));
+      // No clear icon when the field is empty.
+      expect(find.byType(GestureDetector), findsNothing);
+      await tester.enterText(find.byType(EditableText), 'foo');
+      await tester.pump(const Duration(milliseconds: 50));
+      // The clear button is the only GestureDetector wrapped around the
+      // trailing icon when there's text.
+      expect(find.byType(GestureDetector), findsOneWidget);
+      await tester.tap(find.byType(GestureDetector));
+      await tester.pumpAndSettle();
+      expect(values.last, isEmpty);
+    });
+
+    testWidgets('onSubmitted fires when the field is submitted', (tester) async {
+      String? submitted;
+      await tester.pumpWidget(harness(
+        f,
+        ClideFilterBox(
+          onChanged: (_) {},
+          onSubmitted: (v) => submitted = v,
+        ),
+      ));
+      await tester.enterText(find.byType(EditableText), 'submit-me');
+      await tester.testTextInput.receiveAction(TextInputAction.done);
+      await tester.pump();
+      expect(submitted, 'submit-me');
+    });
+  });
+
+  group('ColumnHat', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('left / center / right factories render', (tester) async {
+      final wc = WindowControls();
+      addTearDown(wc.dispose);
+      await tester.pumpWidget(harness(
+        f,
+        Column(children: [
+          SizedBox(width: 200, child: ColumnHat.left(windowControls: wc)),
+          SizedBox(width: 200, child: ColumnHat.center(windowControls: wc, project: 'clide', branch: 'main')),
+          SizedBox(width: 200, child: ColumnHat.right(windowControls: wc)),
+        ]),
+      ));
+      // Center hat renders the joined label.
+      expect(find.text('clide > main'), findsOneWidget);
+    });
+
+    testWidgets('center hat falls back to "clide" with no project/branch', (tester) async {
+      final wc = WindowControls();
+      addTearDown(wc.dispose);
+      await tester.pumpWidget(harness(
+        f,
+        SizedBox(width: 200, child: ColumnHat.center(windowControls: wc)),
+      ));
+      expect(find.text('clide'), findsOneWidget);
+    });
+  });
+
+  group('ClideIconRail', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('renders one button per item, marks the active one, fires onSelect', (tester) async {
+      String? selected;
+      await tester.pumpWidget(harness(
+        f,
+        ClideIconRail(
+          items: const [
+            ClideIconRailItem(id: 'a', icon: PhosphorIcons.folder, tooltip: 'A'),
+            ClideIconRailItem(id: 'b', icon: PhosphorIcons.gitBranch, tooltip: 'B'),
+          ],
+          activeId: 'a',
+          onSelect: (id) => selected = id,
+        ),
+      ));
+      await tester.pumpAndSettle();
+      // Each item exposes a tooltip-labeled semantics button.
+      expect(find.bySemanticsLabel('A'), findsOneWidget);
+      expect(find.bySemanticsLabel('B'), findsOneWidget);
+      await tester.tap(find.bySemanticsLabel('B'));
+      expect(selected, 'b');
+    });
+  });
+
+  group('ClideSpine', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('renders the rotated label + a badge dot when badgeCount > 0', (tester) async {
+      var taps = 0;
+      await tester.pumpWidget(harness(
+        f,
+        SizedBox(
+            height: 200,
+            width: ClideSpine.width,
+            child: ClideSpine(
+              label: 'SIDEBAR',
+              badgeCount: 3,
+              onExpand: () => taps++,
+            )),
+      ));
+      await tester.pumpAndSettle();
+      expect(find.text('SIDEBAR'), findsOneWidget);
+      // Tap to expand.
+      await tester.tap(find.byType(ClideSpine));
+      expect(taps, 1);
+    });
+
+    testWidgets('renders the right-side variant without throwing', (tester) async {
+      await tester.pumpWidget(harness(
+        f,
+        SizedBox(
+            height: 200,
+            width: ClideSpine.width,
+            child: ClideSpine(
+              label: 'CTX',
+              side: SpineSide.right,
+              onExpand: () {},
+            )),
+      ));
+      await tester.pumpAndSettle();
+      expect(find.text('CTX'), findsOneWidget);
+    });
+  });
+
+  group('ClideResizeBorder', () {
+    late KernelFixture f;
+    setUp(() async => f = await KernelFixture.create());
+    tearDown(() async => f.dispose());
+
+    testWidgets('wraps a child and renders 8 resize zones', (tester) async {
+      final wc = WindowControls();
+      addTearDown(wc.dispose);
+      await tester.pumpWidget(harness(
+        f,
+        ClideResizeBorder(
+          windowControls: wc,
+          child: const SizedBox.expand(child: ColoredBox(color: Color(0xFF000000))),
+        ),
+      ));
+      await tester.pumpAndSettle();
+      // 4 corners + 4 edges = 8 zones each with a MouseRegion.
+      expect(find.byType(MouseRegion).evaluate().length, greaterThanOrEqualTo(8));
+    });
+  });
+}