test sweep: cover welcome_view tail paths (T-91)

Eight new widget tests in test/builtin/welcome/widget_test.dart
covering the WelcomeView paths the existing render-it test didn't
reach:

- TIPS card visibility: shown when viewport height > 640, hidden
  when shorter (LayoutBuilder branch).
- Status line tri-state: "checking…" before toolchain resolution,
  "application ok" when all tools present, missing-tools listing
  when some are absent.
- Theme-name link tap fires the theme.pick command via the registry.
- Open folder tap with no native picker (returns null, function
  returns early) and with MissingPluginException (falls through to
  the path dialog via kernel.dialog.show).

Coverage: builtin/welcome/src/welcome_view.dart 84/221 -> 120/221
(54%). Remaining 101 lines are inside the _OpenProjectDialog,
_NotARepoDialog, and recent-project rows — they need either a
DialogHost in the test harness or a populated recents list, which
is materially more setup than the rest of this batch's pattern.

Total coverage 79.34% -> 79.80%.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/builtin/welcome/widget_test.dart

@@ -2,8 +2,10 @@ import 'dart:ui';
 
 import 'package:clide/builtin/welcome/welcome.dart';
 import 'package:clide/builtin/welcome/src/welcome_view.dart';
+import 'package:clide/clide.dart';
 import 'package:clide/extension/extension.dart';
 import 'package:clide/kernel/kernel.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -47,5 +49,107 @@ void main() {
       expect(find.text('IDE for Claude Code CLI'), findsOneWidget);
       expect(find.text('Open folder…'), findsOneWidget);
     });
+
+    testWidgets('TIPS card renders when the viewport is tall enough', (tester) async {
+      tester.view.physicalSize = const Size(1200, 800);
+      tester.view.devicePixelRatio = 1.0;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      expect(find.text('TIPS'), findsOneWidget);
+      expect(find.text('Quick open'), findsOneWidget);
+    });
+
+    testWidgets('TIPS card is hidden when the viewport is short', (tester) async {
+      tester.view.physicalSize = const Size(1200, 500);
+      tester.view.devicePixelRatio = 1.0;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      expect(find.text('TIPS'), findsNothing);
+    });
+
+    testWidgets('status line shows "checking…" before toolchain resolution', (tester) async {
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      expect(find.text('checking…'), findsOneWidget);
+    });
+
+    testWidgets('status line shows "application ok" when all tools resolved', (tester) async {
+      f.services.toolchain.applyResolved(const ResolvedPaths(
+        git: '/usr/bin/git',
+        pql: '/usr/bin/pql',
+        tmux: '/usr/bin/tmux',
+        shell: '/bin/bash',
+      ));
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      expect(find.text('application ok'), findsOneWidget);
+    });
+
+    testWidgets('status line lists missing tools when some are absent', (tester) async {
+      tester.view.physicalSize = const Size(1600, 900);
+      tester.view.devicePixelRatio = 1.0;
+      addTearDown(tester.view.resetPhysicalSize);
+      addTearDown(tester.view.resetDevicePixelRatio);
+      f.services.toolchain.applyResolved(const ResolvedPaths(
+        pql: '/usr/bin/pql',
+      ));
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      expect(find.textContaining('git not found'), findsOneWidget);
+      expect(find.textContaining('tmux not found'), findsOneWidget);
+    });
+
+    testWidgets('theme-name link fires the theme.pick command when tapped', (tester) async {
+      var invocations = 0;
+      f.services.commands.register(CommandContribution(
+        id: 'theme.pick',
+        command: 'theme.pick',
+        title: 'Theme: Pick',
+        run: (_) async {
+          invocations++;
+          return IpcResponse.ok(id: '', data: const {});
+        },
+      ));
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      await tester.tap(find.textContaining('theme:'));
+      await tester.pump();
+      expect(invocations, 1);
+    });
+
+    testWidgets('Open folder tap kicks off the picker flow without throwing', (tester) async {
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('Open folder…'));
+      await tester.pumpAndSettle();
+      // In the test harness, the platform channel returns null (no native
+      // picker, no MissingPluginException), so the function returns
+      // early without raising. The point is just to exercise the path.
+      expect(tester.takeException(), isNull);
+    });
+
+    testWidgets('Open folder opens the fallback dialog when the picker throws MissingPluginException', (tester) async {
+      // Pre-register a mock that throws — emulating a platform without
+      // native picker support.
+      tester.binding.defaultBinaryMessenger.setMockMethodCallHandler(
+        const MethodChannel('clide/window'),
+        (call) async {
+          if (call.method == 'pickDirectory') {
+            throw MissingPluginException();
+          }
+          return null;
+        },
+      );
+      await tester.pumpWidget(harness(f, const WelcomeView()));
+      await tester.pumpAndSettle();
+      await tester.tap(find.text('Open folder…'));
+      await tester.pumpAndSettle();
+      expect(f.services.dialog.isOpen, isTrue);
+      f.services.dialog.dismiss();
+      await tester.pumpAndSettle();
+    });
   });
 }