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_en.arb

@@ -2131,6 +2131,53 @@
   "assistantHintWeb": "Search the web…",
   "assistantSendWeb": "Search",
   "assistantSearchFailed": "The search couldn't be opened.",
+  "assistantChoose": "Who answers",
+  "assistantWebSearch": "Web search",
+  "assistantChooseAgree": "Read and agree first",
+  "@assistantChooseAgree": {"description": "Under an assistant in the field's menu that the person hasn't agreed to yet."},
+  "assistantChooseOwn": "With your key",
+  "assistantHintAsk": "Ask {name}…",
+  "@assistantHintAsk": {"placeholders": {"name": {"type": "String"}}},
+  "assistantSendAsk": "Ask",
+  "assistantScope": "What it may look up",
+  "@assistantScope": {"description": "Tooltip of the scope chip: how far an assistant may look beyond the parts chosen."},
+  "assistantScopeTicked": "Only what I choose",
+  "assistantScopeStudyset": "This studyset",
+  "assistantScopeTree": "Its tree",
+  "assistantScopeLibrary": "Library",
+  "assistantScopeTickedLong": "Only what I choose above",
+  "assistantScopeStudysetLong": "This studyset with its topics",
+  "assistantScopeTreeLong": "Its whole tree, from the top",
+  "assistantScopeLibraryLong": "My whole library",
+  "assistantScopePrivate": "Include private studysets",
+  "assistantScopeWithPrivate": "{scope}, private ones too",
+  "@assistantScopeWithPrivate": {"placeholders": {"scope": {"type": "String"}}},
+  "assistantHistory": "Conversations",
+  "assistantHistoryEmpty": "No conversations yet",
+  "assistantHistoryEmptyHint": "Ask an assistant in the field below.",
+  "assistantHistoryDelete": "Delete conversation",
+  "assistantHistoryDeleteMessage": "“{title}” goes from all your devices.",
+  "@assistantHistoryDeleteMessage": {"placeholders": {"title": {"type": "String"}}},
+  "assistantHistoryDeleteConfirm": "Delete",
+  "assistantGone": "An assistant no longer offered",
+  "assistantGoneNote": "This assistant is no longer offered to you here, so the conversation can't go on.",
+  "assistantNotKept": "Not kept: this device can't encrypt conversations, so this one is gone once you close it.",
+  "assistantFollowUp": "Ask more…",
+  "assistantStop": "Stop",
+  "assistantAnswering": "Answering…",
+  "assistantStopped": "Stopped before it answered.",
+  "assistantStoppedEarly": "It looked things up too often and stopped without an answer.",
+  "assistantNoAnswer": "No answer.",
+  "assistantCopyAnswer": "Copy the answer",
+  "assistantCopied": "Answer copied",
+  "assistantLookedUpStudysets": "Listed {count, plural, =0{no studysets} =1{1 studyset} other{{count} studysets}}",
+  "@assistantLookedUpStudysets": {"placeholders": {"count": {"type": "int"}}},
+  "assistantLookedUpCards": "Looked for “{query}” in cards: {count, plural, =0{none found} =1{1 found} other{{count} found}}",
+  "@assistantLookedUpCards": {"placeholders": {"query": {"type": "String"}, "count": {"type": "int"}}},
+  "assistantLookedUpNotes": "Looked for “{query}” in notes: {count, plural, =0{none found} =1{1 found} other{{count} found}}",
+  "@assistantLookedUpNotes": {"placeholders": {"query": {"type": "String"}, "count": {"type": "int"}}},
+  "assistantLookedUpNote": "Read a note",
+  "assistantLookedUpNoNote": "Looked for a note, found none",
   "settingsSearchEngine": "Search engine",
   "searchEngineDevice": "The device's search",
   "searchEngineCustom": "Your own address",