feat(learn): the assistant answers in the field

The field asks an assistant the instance offers as well as searching the
web (ADR 0021): who answers is picked at its start, the one asked last
first (askWith, a device setting), an assistant not agreed to yet asking
for agreement first. Asking an assistant, every part of the topic may go
along, and one chip leads them with how far it may look (D49), only what
is chosen until the person widens it to the studyset, its tree or the
library, private studysets only where switched on (D50, D8). The
conversation shows in a sheet over the screen (D47), half the height and
dragged up to the full: each question with what went along, the lookups,
the answer as Markdown once whole, follow-ups, Stop, and Try again for a
question that got no answer; a device that can't seal says it keeps
nothing (D52). The field lists the conversations kept (D48), those about
where the person is first, to open again or delete.

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/l10n/app_de.arb

@@ -1817,6 +1817,45 @@
   "assistantHintWeb": "Im Web suchen…",
   "assistantSendWeb": "Suchen",
   "assistantSearchFailed": "Die Suche ließ sich nicht öffnen.",
+  "assistantChoose": "Wer antwortet",
+  "assistantWebSearch": "Websuche",
+  "assistantChooseAgree": "Erst lesen und zustimmen",
+  "assistantChooseOwn": "Mit deinem Schlüssel",
+  "assistantHintAsk": "{name} fragen…",
+  "assistantSendAsk": "Fragen",
+  "assistantScope": "Was er nachschlagen darf",
+  "assistantScopeTicked": "Nur was ich auswähle",
+  "assistantScopeStudyset": "Dieses Lernset",
+  "assistantScopeTree": "Ganzer Baum",
+  "assistantScopeLibrary": "Bibliothek",
+  "assistantScopeTickedLong": "Nur was ich oben auswähle",
+  "assistantScopeStudysetLong": "Dieses Lernset mit seinen Themen",
+  "assistantScopeTreeLong": "Sein ganzer Baum, von oben",
+  "assistantScopeLibraryLong": "Meine ganze Bibliothek",
+  "assistantScopePrivate": "Private Lernsets einbeziehen",
+  "assistantScopeWithPrivate": "{scope}, auch private",
+  "assistantHistory": "Unterhaltungen",
+  "assistantHistoryEmpty": "Noch keine Unterhaltungen",
+  "assistantHistoryEmptyHint": "Frag einen Assistenten im Feld unten.",
+  "assistantHistoryDelete": "Unterhaltung löschen",
+  "assistantHistoryDeleteMessage": "„{title}“ verschwindet von allen deinen Geräten.",
+  "assistantHistoryDeleteConfirm": "Löschen",
+  "assistantGone": "Ein nicht mehr angebotener Assistent",
+  "assistantGoneNote": "Dieser Assistent wird dir hier nicht mehr angeboten, also lässt sich die Unterhaltung nicht fortsetzen.",
+  "assistantNotKept": "Nicht gespeichert: Dieses Gerät kann Unterhaltungen nicht verschlüsseln, also ist diese weg, sobald du sie schließt.",
+  "assistantFollowUp": "Weiter fragen…",
+  "assistantStop": "Anhalten",
+  "assistantAnswering": "Antwortet…",
+  "assistantStopped": "Vor der Antwort angehalten.",
+  "assistantStoppedEarly": "Er hat zu oft nachgeschlagen und ohne Antwort aufgehört.",
+  "assistantNoAnswer": "Keine Antwort.",
+  "assistantCopyAnswer": "Antwort kopieren",
+  "assistantCopied": "Antwort kopiert",
+  "assistantLookedUpStudysets": "{count, plural, =0{Keine Lernsets} =1{1 Lernset} other{{count} Lernsets}} aufgelistet",
+  "assistantLookedUpCards": "Karten nach „{query}“ durchsucht: {count, plural, =0{keine gefunden} =1{1 gefunden} other{{count} gefunden}}",
+  "assistantLookedUpNotes": "Notizen nach „{query}“ durchsucht: {count, plural, =0{keine gefunden} =1{1 gefunden} other{{count} gefunden}}",
+  "assistantLookedUpNote": "Eine Notiz gelesen",
+  "assistantLookedUpNoNote": "Eine Notiz gesucht, keine gefunden",
   "settingsSearchEngine": "Suchmaschine",
   "searchEngineDevice": "Suche des Geräts",
   "searchEngineCustom": "Eigene Adresse",