feat: guided setup — free-text AI path (phase 1.2)

The wizard's first step now offers 'or just describe what you want
to do': the goal goes to the configured system AI, which maps it
onto the menu answers (validated against strict enum whitelists —
a hallucinated value can never reach the engine). The suggestion
comes back as an editable plain-language reflection ('this is how I
read your task') the operator can adjust step-by-step or take to
the same preview/apply the menu path uses. Trust rules per
guided-setup.md: suggestion only (never auto-apply), a privacy line
states whether the description is processed locally or sent to a
provider, and without a configured system AI the section explains
that the menu always works — no dead end.

Signed-off-by: flemming-it <stefan.a.flemming@googlemail.com>

test/guided_setup_test.dart

@@ -176,4 +176,88 @@ void main() {
       expect(find.text('text.extract installieren'), findsNothing);
     },
   );
+
+  testWidgets(
+    'step 1 offers the free-text path with an honest no-AI fallback hint',
+    (tester) async {
+      await tester.pumpWidget(
+        MaterialApp(
+          locale: const Locale('de'),
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          home: Builder(
+            builder: (context) => Scaffold(
+              body: Center(
+                child: ElevatedButton(
+                  onPressed: () => showDialog<void>(
+                    context: context,
+                    builder: (_) =>
+                        const GuidedSetupDialog(debugSkipAiProbe: true),
+                  ),
+                  child: const Text('open'),
+                ),
+              ),
+            ),
+          ),
+        ),
+      );
+      await tester.tap(find.text('open'));
+      await tester.pumpAndSettle();
+
+      expect(
+        find.text('Oder beschreiben Sie einfach, was Sie vorhaben'),
+        findsOneWidget,
+      );
+      // No system AI configured → honest fallback: the menu always
+      // works; no dead end, no disabled mystery button.
+      expect(
+        find.textContaining('Die Auswahl oben funktioniert immer'),
+        findsOneWidget,
+      );
+      expect(find.text('Vorschlagen lassen'), findsNothing);
+    },
+  );
+
+  group('parseSetupSuggestion', () {
+    test('accepts a valid JSON object embedded in prose', () {
+      final r = parseSetupSuggestion(
+        'Sure! Here is the mapping:\n'
+        '{"scenario":"regulated-production","intent":"classify-documents",'
+        '"target":"home-server","require_approval":true,'
+        '"data_must_stay_local":false}\n'
+        'Let me know if you need anything else.',
+      );
+      expect(r, isNotNull);
+      expect(r!['scenario'], 'regulated-production');
+      expect(r['intent'], 'classify-documents');
+      expect(r['target'], 'home-server');
+      expect(r['require_approval'], true);
+      expect(r['data_must_stay_local'], false);
+    });
+
+    test('rejects hallucinated enum values', () {
+      expect(
+        parseSetupSuggestion(
+          '{"scenario":"world-domination","intent":"hello-world",'
+          '"target":"this-laptop"}',
+        ),
+        isNull,
+      );
+    });
+
+    test('rejects non-JSON replies', () {
+      expect(parseSetupSuggestion('I cannot help with that.'), isNull);
+      expect(parseSetupSuggestion('{broken json'), isNull);
+    });
+
+    test('missing booleans default to false', () {
+      final r = parseSetupSuggestion(
+        '{"scenario":"trying-out","intent":"hello-world",'
+        '"target":"this-laptop"}',
+      );
+      expect(r, isNotNull);
+      expect(r!['require_approval'], false);
+      expect(r['data_must_stay_local'], false);
+    });
+  });
 }