Sandbox: keep a launch intent for the FGS

2811f78 hid the sandbox from the launcher by removing its LAUNCHER
category. flutter_foreground_task builds its notification from
getLaunchIntentForPackage, which then returned null; the NPE meant
startForeground never ran and Android killed the app with
ForegroundServiceDidNotStartInTimeException on the first set tap and
on every resume. A separate MAIN+INFO filter (checked before LAUNCHER)
restores the intent and leaves the launcher entry hidden. The daily
flavor keeps LAUNCHER and was never affected.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WzxdWYdwRAtMg7ki6TKxuU

stronglift_replacement/workout_app/android/app/src/sandbox/AndroidManifest.xml

@@ -14,6 +14,14 @@
                     android:name="android.intent.category.LAUNCHER"
                     tools:node="remove"/>
             </intent-filter>
+            <!-- Load-bearing: getLaunchIntentForPackage tries INFO before
+                 LAUNCHER, and flutter_foreground_task's notification needs
+                 that intent. Without it the service never calls
+                 startForeground and Android kills the app. -->
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.INFO"/>
+            </intent-filter>
         </activity>
     </application>
 </manifest>

stronglift_replacement/workout_app/test/sandbox/sandbox_manifest_test.dart

@@ -0,0 +1,42 @@
+// The sandbox flavor is hidden from the launcher, which removes the only
+// intent filter `getLaunchIntentForPackage` used to find. flutter_foreground_task
+// builds its notification from that intent; null made `startForeground` throw,
+// so Android killed the app with ForegroundServiceDidNotStartInTimeException.
+import 'dart:io';
+
+import 'package:flutter_test/flutter_test.dart';
+
+/// Relative to the package root, which is `flutter test`'s cwd.
+const _manifestPath = 'android/app/src/sandbox/AndroidManifest.xml';
+
+void main() {
+  late String manifest;
+
+  setUpAll(() => manifest = File(_manifestPath).readAsStringSync());
+
+  test('the sandbox stays out of the launcher', () {
+    expect(
+      manifest,
+      matches(
+        RegExp(
+          r'category\s+android:name="android\.intent\.category\.LAUNCHER"'
+          r'\s+tools:node="remove"',
+        ),
+      ),
+    );
+  });
+
+  test('a MAIN + INFO filter keeps the package launchable by intent', () {
+    final filters = RegExp(r'<intent-filter>(.*?)</intent-filter>', dotAll: true)
+        .allMatches(manifest)
+        .map((m) => m.group(1)!);
+    expect(
+      filters.where(
+        (f) =>
+            f.contains('android.intent.action.MAIN') &&
+            f.contains('android.intent.category.INFO'),
+      ),
+      isNotEmpty,
+    );
+  });
+}