chore(studio): RadioGroup migration + second integration test

Two clean-ups:

- `fai_system_ai_editor.dart` uses the new `RadioGroup<T>`
  ancestor pattern Material 3 introduced after Flutter 3.32.
  Same UX (three radios for off/redacted/full), no
  deprecation warnings, `flutter analyze` is now zero-issue
  for the whole project.
- New `install_install_planned_test.dart` asserts that
  installing a `planned` seed entry surfaces a clear,
  human-readable error class (no panic, no silent success).
  Locks in the failed-precondition path Studio's
  friendly-error mapper depends on.

Integration test suite is now 3 scenarios:
  - capabilities_test.dart: system.approval+kind tag
  - install_install_planned_test.dart: planned-install error

All run against a fresh `fai serve` subprocess via
HubFixture, ~2 s total.

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

lib/widgets/fai_system_ai_editor.dart

@@ -553,7 +553,17 @@ class _PrivacyModeChips extends StatelessWidget {
         l.systemAiPrivacyFullDesc,
       ),
     ];
-    return Column(
+    // Material 3 deprecated per-Radio `groupValue` / `onChanged`
+    // after Flutter 3.32. The modern pattern wraps the radios in
+    // a RadioGroup<T> ancestor that owns the selection + change
+    // callback; the individual Radio widgets only declare their
+    // value. Same UX, no deprecation warnings.
+    return RadioGroup<String>(
+      groupValue: value,
+      onChanged: (v) {
+        if (v != null) onChanged(v);
+      },
+      child: Column(
         crossAxisAlignment: CrossAxisAlignment.start,
         children: [
           Text(
@@ -576,11 +586,7 @@ class _PrivacyModeChips extends StatelessWidget {
                 ),
                 child: Row(
                   children: [
-                  Radio<String>(
+                    Radio<String>(value: wire),
-                    value: wire,
-                    groupValue: value,
-                    onChanged: (v) => onChanged(v ?? wire),
-                  ),
                     Expanded(
                       child: Column(
                         crossAxisAlignment: CrossAxisAlignment.start,
@@ -600,6 +606,7 @@ class _PrivacyModeChips extends StatelessWidget {
               ),
             ),
         ],
+      ),
     );
   }
 }

test/integration/install_install_planned_test.dart

@@ -0,0 +1,42 @@
+// Integration test: install_module against a `planned` seed
+// entry must fail with a clear, human-readable error class —
+// not a panic, not a silent success.
+//
+// Why this matters: planned modules are listed in the Store
+// but have no wasm_url. The old behaviour was a server-side
+// panic on resolve_install_source(); the new contract emits a
+// FAILED_PRECONDITION with "no installable version" so
+// Studio's friendly-error mapper can show a usable message.
+
+import 'package:flutter_test/flutter_test.dart';
+
+import 'hub_fixture.dart';
+
+void main() {
+  test('install_module on a planned entry surfaces a clear error',
+      () async {
+    final fixture = await HubFixture.start();
+    if (fixture == null) return;
+    try {
+      // web.scrape is `planned` in the seed and has no
+      // wasm_url. The hub resolves the name through the store
+      // index, finds the entry, then fails at the
+      // "no installable version" check.
+      try {
+        await fixture.client.installModule(source: 'web.scrape');
+        fail('install_module should not succeed for a planned entry');
+      } catch (e) {
+        final msg = e.toString();
+        expect(
+          msg.contains('no installable version') ||
+              msg.contains('not yet published'),
+          isTrue,
+          reason:
+              'Expected a clear planned-status error, got: $msg',
+        );
+      }
+    } finally {
+      await fixture.dispose();
+    }
+  });
+}