merge successful tool call + result into one card (T-262)

A successful tool call now renders as a single merged card instead of a
separate call card + result card:

- ConversationCard gains a trailing header status slot (success check /
  error cross, semantics-labelled) and optional labelled extra body
  segments (P1 + P2 — reused by T-263's Agent card).
- conversation_view builds a reverse toolUseId→result lookup, folds a
  successful result into its call card as a colorized ClideCodeBlock
  (Read → file grammar, Bash → shell, else text), and suppresses the
  standalone success result in _visibleItems. Errors stay a separate
  prominent red card, now with a matching red header mark (note C).
- Suppression happens before grouping, so a merged success result is no
  longer a separate activity-cluster step (note D).

Tests: card status-mark + segment coverage, merged-fold + language
inference + in-flight/orphan/error cases, cluster non-double-count, and a
golden for the merged card (collapsed + expanded + error).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/builtin/claude/conversation_card_test.dart

@@ -283,6 +283,68 @@ void main() {
     expect(find.text('result'), findsOneWidget);
   });
 
+  testWidgets('status: success renders a "succeeded" semantics mark in the header (T-262)', (tester) async {
+    final handle = tester.ensureSemantics();
+    await tester.pumpWidget(harness(
+      f,
+      const ConversationCard(
+        variant: ConversationCardVariant.bordered,
+        accent: Color(0xFFFFFFFF),
+        label: 'Bash',
+        status: ConversationCardStatus.success,
+        body: Text('body', textDirection: TextDirection.ltr),
+      ),
+    ));
+    await tester.pump();
+    expect(find.bySemanticsLabel('succeeded'), findsOneWidget);
+    expect(find.bySemanticsLabel('failed'), findsNothing);
+    handle.dispose();
+  });
+
+  testWidgets('status: error renders a "failed" semantics mark; none renders nothing (T-262)', (tester) async {
+    final handle = tester.ensureSemantics();
+    await tester.pumpWidget(harness(
+      f,
+      const ConversationCard(
+        variant: ConversationCardVariant.bordered,
+        accent: Color(0xFFFFFFFF),
+        label: 'Bash',
+        status: ConversationCardStatus.error,
+        body: Text('body', textDirection: TextDirection.ltr),
+      ),
+    ));
+    await tester.pump();
+    expect(find.bySemanticsLabel('failed'), findsOneWidget);
+    expect(find.bySemanticsLabel('succeeded'), findsNothing);
+    handle.dispose();
+  });
+
+  testWidgets('extraSegments render below the body with their sub-label when expanded (T-262)', (tester) async {
+    await tester.pumpWidget(harness(
+      f,
+      const ConversationCard(
+        variant: ConversationCardVariant.bordered,
+        accent: Color(0xFFFFFFFF),
+        label: 'Read',
+        collapsible: true,
+        collapsedByDefault: true,
+        body: Text('the call', textDirection: TextDirection.ltr),
+        extraSegments: [CardSegment(label: 'result', child: Text('the output', textDirection: TextDirection.ltr))],
+      ),
+    ));
+    await tester.pump();
+    // Collapsed: neither the body nor the segment shows.
+    expect(find.text('the call'), findsNothing);
+    expect(find.text('result'), findsNothing);
+    expect(find.text('the output'), findsNothing);
+
+    await tester.tap(find.bySemanticsLabel('Expand'));
+    await tester.pump();
+    expect(find.text('the call'), findsOneWidget); // primary body
+    expect(find.text('result'), findsOneWidget); // segment sub-label
+    expect(find.text('the output'), findsOneWidget); // segment child
+  });
+
   testWidgets('bare variant renders content without frame decoration', (tester) async {
     await tester.pumpWidget(harness(
       f,

test/builtin/claude/conversation_view_test.dart

@@ -177,7 +177,9 @@ void main() {
           tester,
           [
             _tool('Bash', const {'command': 'echo hi'}),
-            _result('hi'),
+            // A second, distinct in-flight tool call (T-262 folds a success
+            // result into its call card, so two *calls* are what make 2 steps).
+            AssistantToolUse(uuid: 'tu2', timestamp: _t, isSidechain: false, toolUseId: 'x2', name: 'Read', input: const {'file_path': '/a'}),
           ],
           foldLevel: FoldLevel.tools);
       // Collapsed by default: one card with a step count, not the raw rows.
@@ -189,6 +191,21 @@ void main() {
       expect(find.bySemanticsLabel('Activity, 2 steps, expanded'), findsOneWidget);
     });
 
+    testWidgets('a folded success result is not a separate step — merged into its call (T-262 note D)', (tester) async {
+      await pumpWith(
+          tester,
+          [
+            _tool('Bash', const {'command': 'echo hi'}),
+            _result('hi there'),
+          ],
+          foldLevel: FoldLevel.tools);
+      // The call + its success result is ONE unit now: 1 step, not 2.
+      expect(find.text('1 step'), findsOneWidget);
+      expect(find.text('2 steps'), findsNothing);
+      // The result is not double-rendered: no standalone result card.
+      expect(find.text('Bash · result'), findsNothing);
+    });
+
     testWidgets('an image card renders with the "image" label, the file, and its caption (T-249)', (tester) async {
       await pumpWith(tester, [_image('/no/such/file.png', caption: 'before the fix')]);
       expect(find.text('image'), findsOneWidget);
@@ -247,8 +264,9 @@ void main() {
       expect(find.text('claude'), findsOneWidget);
       expect(find.text('thinking'), findsOneWidget);
       expect(find.text('Bash'), findsOneWidget);
-      // Result labels now include the paired tool name (T-168).
-      expect(find.text('Bash · result'), findsOneWidget);
+      // T-262: a successful result folds into the tool card (no standalone
+      // "Bash · result"); a failed result keeps its prominent standalone card.
+      expect(find.text('Bash · result'), findsNothing);
       expect(find.text('Bash · error'), findsOneWidget);
     });
 
@@ -289,8 +307,12 @@ void main() {
         hiddenToolUseIds: {'x1'},
         toolUseOutcomes: {'x1': true}, // approved
       );
+      final handle = tester.ensureSemantics();
       expect(find.text('Write'), findsOneWidget); // shown (resolved)
-      expect(find.byType(ClideIcon), findsOneWidget); // collapsed caret
+      expect(find.bySemanticsLabel('Expand'), findsOneWidget); // collapsed caret
+      // T-262: the resolved card also folds its result + a success check.
+      expect(find.bySemanticsLabel('succeeded'), findsOneWidget);
+      handle.dispose();
     });
 
     testWidgets('an injected user message renders as a muted "context" card, not "you"', (tester) async {
@@ -323,12 +345,63 @@ void main() {
       expect(find.text('/foo/bar.dart'), findsOneWidget);
     });
 
-    testWidgets('result label includes paired tool name (T-168)', (tester) async {
+    testWidgets('a successful result folds into the tool-use card with a check (T-262)', (tester) async {
+      final handle = tester.ensureSemantics();
       await pumpWith(tester, [
-        _tool('Read', {'file_path': '/x'}),
-        _result('file content'),
+        _tool('Read', {'file_path': '/foo/bar.dart'}),
+        _result('final answer = 42;'),
       ]);
-      expect(find.text('Read · result'), findsOneWidget);
+      // No standalone success result card — it's folded into the Read card.
+      expect(find.text('Read · result'), findsNothing);
+      // The merged card shows a success check.
+      expect(find.bySemanticsLabel('succeeded'), findsOneWidget);
+      // Collapsed by default: neither the call body nor the result is shown yet.
+      expect(find.text('final answer = 42;'), findsNothing);
+
+      // Expand: the call segment, a "result" sub-label, and the folded result
+      // as a colorized code block (Read → grammar from the .dart path).
+      await tester.tap(find.bySemanticsLabel('Expand'));
+      await tester.pumpAndSettle();
+      expect(find.text('result'), findsOneWidget); // segment sub-label
+      final blocks = tester.widgetList<ClideCodeBlock>(find.byType(ClideCodeBlock)).toList();
+      expect(blocks.any((b) => b.language == 'dart' && b.source == 'final answer = 42;'), isTrue);
+      handle.dispose();
+    });
+
+    testWidgets('Bash result folds as a bash code block; in-flight call has no check (T-262)', (tester) async {
+      final handle = tester.ensureSemantics();
+      // In-flight: a call with no result yet → no check, no folded result.
+      await pumpWith(tester, [
+        _tool('Bash', {'command': 'ls'})
+      ]);
+      expect(find.bySemanticsLabel('succeeded'), findsNothing);
+      expect(find.bySemanticsLabel('failed'), findsNothing);
+      handle.dispose();
+    });
+
+    testWidgets('Bash success result infers the bash language for the folded block (T-262)', (tester) async {
+      await pumpWith(tester, [
+        _tool('Bash', {'command': 'echo hi'}),
+        _result('hi\nthere'),
+      ]);
+      await tester.tap(find.bySemanticsLabel('Expand'));
+      await tester.pumpAndSettle();
+      final blocks = tester.widgetList<ClideCodeBlock>(find.byType(ClideCodeBlock)).toList();
+      expect(blocks.any((b) => b.language == 'bash' && b.source == 'hi\nthere'), isTrue);
+    });
+
+    testWidgets('a failed result is NOT folded: standalone error card + red header mark (T-262)', (tester) async {
+      final handle = tester.ensureSemantics();
+      await pumpWith(tester, [
+        _tool('Bash', {'command': 'boom'}),
+        _result('permission denied', isError: true),
+      ]);
+      // The error stays a separate prominent card…
+      expect(find.text('Bash · error'), findsOneWidget);
+      expect(find.text('permission denied'), findsOneWidget);
+      // …and the call card carries a red failure mark for symmetry (note C).
+      expect(find.bySemanticsLabel('failed'), findsOneWidget);
+      handle.dispose();
     });
 
     testWidgets('error result label includes paired tool name (T-168)', (tester) async {

test/goldens/conversation_card_goldens_test.dart

@@ -0,0 +1,78 @@
+import 'package:alchemist/alchemist.dart';
+import 'package:clide/builtin/claude/src/conversation_card.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() {
+  late KernelFixture f;
+
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() async => f.dispose());
+
+  goldenTest(
+    'ConversationCard merged tool card (T-262): status mark + folded result segment',
+    fileName: 'conversation_card_merged',
+    builder: () => GoldenTestGroup(
+      columns: 1,
+      children: [
+        GoldenTestScenario(
+          name: 'success / collapsed (check + summary)',
+          child: _wrap(
+            f,
+            const ConversationCard(
+              variant: ConversationCardVariant.bordered,
+              accent: Color(0xFF4C9AFF),
+              label: 'Read',
+              status: ConversationCardStatus.success,
+              collapsible: true,
+              collapsedByDefault: true,
+              collapsedSummary: '/lib/main.dart',
+              body: Text('/lib/main.dart', textDirection: TextDirection.ltr),
+              extraSegments: [CardSegment(label: 'result', child: Text('void main() {}', textDirection: TextDirection.ltr))],
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'success / expanded (call → result segment)',
+          child: _wrap(
+            f,
+            const ConversationCard(
+              variant: ConversationCardVariant.bordered,
+              accent: Color(0xFF4C9AFF),
+              label: 'Read',
+              status: ConversationCardStatus.success,
+              collapsible: true,
+              collapsedByDefault: false,
+              body: Text('/lib/main.dart', textDirection: TextDirection.ltr),
+              extraSegments: [CardSegment(label: 'result', child: Text('void main() {}', textDirection: TextDirection.ltr))],
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'error / header mark (call card stays separate from the red result card)',
+          child: _wrap(
+            f,
+            const ConversationCard(
+              variant: ConversationCardVariant.bordered,
+              accent: Color(0xFF4C9AFF),
+              label: 'Bash',
+              status: ConversationCardStatus.error,
+              collapsible: true,
+              collapsedByDefault: true,
+              collapsedSummary: 'cat nonexistent',
+              body: Text('cat nonexistent', textDirection: TextDirection.ltr),
+            ),
+          ),
+        ),
+      ],
+    ),
+  );
+}
+
+Widget _wrap(KernelFixture f, Widget child) => SizedBox(
+      width: 360,
+      child: harness(f, child),
+    );