test sweep: icons, log.trace, DialogHost, FilesDropped getters (T-91)

Three small additions to push coverage toward the 90% target:

- test/widgets/icons_test.dart: one sweep test calling .paint() on
  every custom ClideIconPainter (Check, ChevronRight, ChevronDown,
  Dot, Folder, Gear, GitBranch, Plug, Search, Terminal, Warning).
- log_test: Logger.trace covered at minLevel.trace + filtered out
  at minLevel.info.
- services_bigger_test: DialogRouter.current getter; DialogHost
  widget rendered with backdrop + inner builder, then dismissed
  through the router. Plus FilesDropped subsystem/kind getters
  exercised through the existing notifyDropped test.

Coverage 89.08% -> 89.93%.

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

test/widgets/icons_test.dart

@@ -0,0 +1,43 @@
+/// Smoke tests for the custom paint icons under `lib/widgets/src/icons/`.
+/// Each paint() call runs against a real PictureRecorder canvas to verify
+/// it doesn't throw and to fill in lcov.
+library;
+
+import 'dart:ui';
+
+import 'package:clide/widgets/src/icons/check.dart';
+import 'package:clide/widgets/src/icons/chevron.dart';
+import 'package:clide/widgets/src/icons/dot.dart';
+import 'package:clide/widgets/src/icons/folder.dart';
+import 'package:clide/widgets/src/icons/gear.dart';
+import 'package:clide/widgets/src/icons/git_branch.dart';
+import 'package:clide/widgets/src/icons/plug.dart';
+import 'package:clide/widgets/src/icons/search.dart';
+import 'package:clide/widgets/src/icons/terminal_icon.dart';
+import 'package:clide/widgets/src/icons/warning.dart';
+import 'package:test/test.dart';
+
+Canvas _canvas() => Canvas(PictureRecorder());
+
+void main() {
+  const color = Color(0xFF000000);
+
+  test('every custom icon painter renders without throwing', () {
+    const painters = [
+      CheckIcon(),
+      ChevronRightIcon(),
+      ChevronDownIcon(),
+      DotIcon(),
+      FolderIcon(),
+      GearIcon(),
+      GitBranchIcon(),
+      PlugIcon(),
+      SearchIcon(),
+      TerminalIcon(),
+      WarningIcon(),
+    ];
+    for (final p in painters) {
+      p.paint(_canvas(), color);
+    }
+  });
+}