fix(app,learn,meditate): a device without speech recognition says so, and how to get one

On GrapheneOS, which installs no recogniser, the microphone did nothing
and stayed listening: speech_to_text's initialize throws a
PlatformException (recognizerNotAvailable) there rather than answering
false, and DeviceSpeechInput let it through. A listen now answers how it
went (SpeechStart: listening, noRecognizer, unavailable) and never
throws; Learn's field and Meditate's dream say that no speech
recognition is installed and name two to install (FUTO Voice Input,
Google's speech services), in halkyon_app's texts. It also passes
androidNoBluetooth, as the apps declare no Bluetooth permission the
plugin would otherwise ask for.

Whats-New: Where the device has no speech recognition, the microphone says so and how to get one.
Whats-New-De: Wo das Gerät keine Spracherkennung hat, sagt das Mikrofon das und wie du eine bekommst.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/learn/halkyon_learn_flutter/lib/src/feature/assistant/widget/composer.dart

@@ -372,6 +372,7 @@ class _SpeakOrSendState() extends State<SpeakOrSend> {
   Future<void> _listen() async {
     final messenger = ScaffoldMessenger.of(context);
     final l10n = AppLocalizations.of(context);
+    final words = HalkyonAppLocalizations.of(context);
     final before = widget.controller.text.trimRight();
     _before = before.isEmpty ? '' : '$before ';
     setState(() => _listening = true);
@@ -392,10 +393,15 @@ class _SpeakOrSendState() extends State<SpeakOrSend> {
         }
       },
     );
-    if (!listens && mounted) {
+    if (!listens.listens && mounted) {
       setState(() => _listening = false);
       messenger.showSnackBar(
-        SnackBar(content: Text(l10n.assistantSpeechUnavailable)),
+        SnackBar(
+          content: Text(switch (listens) {
+            SpeechStart.noRecognizer => words.speechNoRecognizer,
+            _ => l10n.assistantSpeechUnavailable,
+          }),
+        ),
       );
     }
   }