feat(todo): quick add's last button dictates the title while it is empty (ADR 0033, D29)

As Todoist's bar and Learn's assistant field (ADR 0021, D69): while the
title is empty its last button is the microphone, filled as the send
button is, dictating where the cursor stands and listening again after
each pause through halkyon_app's Dictation; what is said is read as if
typed. It shows a stop button while listening and the send button once
there is text, or alone where nothing recognises speech (Linux). A
phone without a recogniser is told how to get one.

Todo gets the device's speech input in its dependencies, and declares
the microphone and the recognition service on Android, the usage texts
on iOS and macOS and the audio input entitlement on macOS, as Learn
does.

Whats-New: Add task's last button is a microphone while the task has no name yet: say the task, dates included.
Whats-New-De: Der letzte Knopf von „Aufgabe hinzufügen“ ist ein Mikrofon, solange die Aufgabe noch keinen Namen hat: Sprich die Aufgabe, Daten eingeschlossen.

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/todo/halkyon_todo_flutter/lib/l10n/app_de.arb

@@ -181,6 +181,9 @@
   "swipeDate": "Datum",
   "tasksMenu": "Mehr",
   "quickAddMore": "Mehr",
+  "quickAddSpeak": "Aufgabe diktieren",
+  "quickAddStopListening": "Zuhören beenden",
+  "quickAddSpeechUnavailable": "Dieses Gerät kann gerade nicht zuhören. Prüfe, ob die App das Mikrofon nutzen darf und die Spracherkennung an ist.",
   "quickAddTokenHint": "Tippe ein hervorgehobenes Wort an oder drücke direkt danach die Rücktaste, um es als Text zu behalten.",
   "deadlineTitle": "Frist",
   "orderChanged": "Reihenfolge geändert",