fixed chat bubble link styling and gesture handling, and added android package visibility for common schemes

android/app/src/main/AndroidManifest.xml

@@ -73,16 +73,34 @@
                 android:resource="@xml/timetable_week_widget_info" />
         </receiver>
     </application>
-    <!-- Required to query activities that can process text, see:
-         https://developer.android.com/training/package-visibility?hl=en and
-         https://developer.android.com/reference/android/content/Intent#ACTION_PROCESS_TEXT.
-
-         In particular, this is used by the Flutter engine in io.flutter.plugin.text.ProcessTextPlugin. -->
+    <!-- Required so url_launcher / can_launch can actually see browsers,
+         mail clients and dialers under Android 11+ package-visibility rules
+         (otherwise UrlLauncher logs "component name for ... is null" and
+         link taps in Talk silently do nothing). The PROCESS_TEXT intent is
+         needed by io.flutter.plugin.text.ProcessTextPlugin (selection
+         menu).
+         See https://developer.android.com/training/package-visibility -->
     <queries>
         <intent>
             <action android:name="android.intent.action.PROCESS_TEXT"/>
             <data android:mimeType="text/plain"/>
         </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW"/>
+            <data android:scheme="https"/>
+        </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW"/>
+            <data android:scheme="http"/>
+        </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW"/>
+            <data android:scheme="mailto"/>
+        </intent>
+        <intent>
+            <action android:name="android.intent.action.VIEW"/>
+            <data android:scheme="tel"/>
+        </intent>
     </queries>
     <uses-permission android:name="android.permission.INTERNET"/>
     <!-- Workmanager periodic widget refresh needs to reschedule after device