test(editor): cover quick-fix exposure + driver approval contract

Two new test files:

  - fix_dialog_test.dart — surface tests for the controller API
    the new Fix dialog reads: fixesFor() returns the analyzer-
    attached list, analyzerErrorCount tracks errors, and the
    English AnalyzerStrings produce the labels the dialog
    renders ('Install <cap>', 'Add source for <cap>…', etc).
  - inline_approval_test.dart — covers the FlowRunDriver
    approval hooks added in 0.21.0. Validates the default
    stubs throw UnsupportedError (so legacy hosts surface in
    CI rather than at runtime) and that a fake driver
    implementation can drive the happy + reject paths.

44 editor tests green.

Signed-off-by: flemming-it <sf@flemming.it>

test/fix_dialog_test.dart

@@ -0,0 +1,67 @@
+// Surface-level tests for the diagnostic-strip Fix dialog
+// support. The dialog itself is a private widget; this file
+// exercises the controller-side API the dialog reads (issues,
+// fixesFor, analyzerErrorCount, AnalyzerStrings) so a future
+// regression on the data flow surfaces in CI.
+
+import 'package:fai_studio_flow_editor/src/flow_yaml_controller.dart';
+import 'package:fai_studio_flow_editor/src/l10n.dart';
+import 'package:fai_studio_flow_editor/src/quick_fix.dart';
+import 'package:flutter_code_editor/flutter_code_editor.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('FlowYamlCodeController quick-fix exposure', () {
+    test('fixesFor returns the analyzer-attached list', () async {
+      final c = FlowYamlCodeController(
+        availableCapabilities: () => const <String>['debug.echo'],
+        storeCapabilities: () => const <String>['text.classify'],
+      );
+      addTearDown(c.dispose);
+      c.fullText = '''
+name: hello
+steps:
+  - id: c
+    use: text.classify@^1
+''';
+      // Wait for the analyzer's debounce.
+      await Future.delayed(const Duration(milliseconds: 700));
+      final issues = c.analysisResult.issues;
+      expect(
+        issues,
+        isNotEmpty,
+        reason: 'analyzer should flag the unknown capability',
+      );
+      final fixes = c.fixesFor(issues.first);
+      expect(fixes, hasLength(1));
+      expect(fixes.first, isA<InstallCapabilityFix>());
+    });
+
+    test('analyzerErrorCount tracks error severity', () async {
+      final c = FlowYamlCodeController(
+        availableCapabilities: () => const <String>['debug.echo'],
+      );
+      addTearDown(c.dispose);
+      expect(c.analysisResult.issues, isEmpty);
+      c.fullText = '''
+steps:
+  - id: x
+    use: nope@^1
+''';
+      await Future.delayed(const Duration(milliseconds: 700));
+      final errors = c.analysisResult.issues
+          .where((i) => i.type == IssueType.error)
+          .length;
+      expect(errors, greaterThan(0));
+    });
+
+    test('AnalyzerStrings.english produces the expected fix labels', () {
+      final strings = AnalyzerStrings.english;
+      expect(strings.fixInstallCap('text.echo'), 'Install text.echo');
+      expect(strings.fixAddSource('text.echo'), 'Add source for text.echo…');
+      expect(strings.fixChangeTo('bytes'), 'Change to "bytes"');
+      expect(strings.fixUseInstead('text.echo@^0.1'),
+          'Use "text.echo@^0.1"');
+    });
+  });
+}