feat(learn): an assistant reads PDFs' pages, and sees images the person chooses or approves

ADR 0021, D12: text first. Lookups find a studyset's PDFs and read a page's
text as PDFium extracts it. An assistant that reads images is offered a
card's images as chips, and may ask to see a card's image or a PDF's page
drawn whole; the conversation asks the person each time (Show it, Don't
show) and sends nothing meanwhile. Images go only as png, jpeg, gif or webp
of at most 5 MB, are never kept in a turn, and a follow-up goes without them.

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

@@ -1814,6 +1814,7 @@
   "assistantLineExplanation": "Erklärung: {text}",
   "assistantLineDescription": "Beschreibung: {text}",
   "assistantChipStudyset": "Lernset: {title}",
+  "assistantChipImage": "Bild {number}",
   "assistantHintWeb": "Im Web suchen…",
   "assistantSendWeb": "Suchen",
   "assistantSearchFailed": "Die Suche ließ sich nicht öffnen.",
@@ -1858,6 +1859,18 @@
   "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",
+  "assistantListedPdfs": "{count, plural, =0{Keine PDFs} =1{1 PDF} other{{count} PDFs}} aufgelistet",
+  "assistantLookedUpPdfs": "PDFs nach „{query}“ durchsucht: {count, plural, =0{keine gefunden} =1{1 gefunden} other{{count} gefunden}}",
+  "assistantLookedUpPage": "Eine Seite einer PDF gelesen",
+  "assistantLookedUpNoPage": "Eine Seite einer PDF gesucht, nicht lesbar",
+  "assistantShownImage": "Hat ein Bild gesehen, das du freigegeben hast",
+  "assistantNotShownImage": "Hat ein Bild nicht gesehen",
+  "assistantShownPage": "Hat eine Seite gesehen, die du freigegeben hast",
+  "assistantNotShownPage": "Hat eine Seite nicht gesehen",
+  "assistantImageAskCard": "{name} möchte Bild {number} der Karte „{title}“ sehen.",
+  "assistantImageAskPage": "{name} möchte Seite {page} von „{title}“ als Bild sehen.",
+  "assistantImageShow": "Zeigen",
+  "assistantImageDontShow": "Nicht zeigen",
   "assistantPrivateTitle": "{count, plural, =1{Ein privates Lernset an {name} senden?} other{Private Lernsets an {name} senden?}}",
   "assistantPrivateGranted": "{count, plural, =1{Es ist Ende-zu-Ende-verschlüsselt, sodass nicht einmal {instance} es lesen kann. Was {name} darin nachschlägt oder was du daraus auswählst, geht durch {instance}, das nichts davon aufbewahrt, an {host}, wo es nach den Bedingungen des Anbieters gelesen wird.} other{Sie sind Ende-zu-Ende-verschlüsselt, sodass nicht einmal {instance} sie lesen kann. Was {name} darin nachschlägt oder was du daraus auswählst, geht durch {instance}, das nichts davon aufbewahrt, an {host}, wo es nach den Bedingungen des Anbieters gelesen wird.}}",
   "assistantPrivateOwn": "{count, plural, =1{Es ist Ende-zu-Ende-verschlüsselt, sodass nicht einmal die Instanz es lesen kann. Was {name} darin nachschlägt oder was du daraus auswählst, geht direkt an {host}, wo es nach den Bedingungen des Anbieters gelesen wird.} other{Sie sind Ende-zu-Ende-verschlüsselt, sodass nicht einmal die Instanz sie lesen kann. Was {name} darin nachschlägt oder was du daraus auswählst, geht direkt an {host}, wo es nach den Bedingungen des Anbieters gelesen wird.}}",

apps/learn/halkyon_learn_flutter/lib/l10n/app_en.arb

@@ -2128,6 +2128,8 @@
   "@assistantLineDescription": {"placeholders": {"text": {"type": "String"}}},
   "assistantChipStudyset": "Studyset: {title}",
   "@assistantChipStudyset": {"placeholders": {"title": {"type": "String"}}},
+  "assistantChipImage": "Image {number}",
+  "@assistantChipImage": {"description": "A chip sending an image on the card (ADR 0021, D12).", "placeholders": {"number": {"type": "int"}}},
   "assistantHintWeb": "Search the web…",
   "assistantSendWeb": "Search",
   "assistantSearchFailed": "The search couldn't be opened.",
@@ -2182,6 +2184,22 @@
   "@assistantLookedUpNotes": {"placeholders": {"query": {"type": "String"}, "count": {"type": "int"}}},
   "assistantLookedUpNote": "Read a note",
   "assistantLookedUpNoNote": "Looked for a note, found none",
+  "assistantListedPdfs": "Listed {count, plural, =0{no PDFs} =1{1 PDF} other{{count} PDFs}}",
+  "@assistantListedPdfs": {"placeholders": {"count": {"type": "int"}}},
+  "assistantLookedUpPdfs": "Looked for “{query}” in PDFs: {count, plural, =0{none found} =1{1 found} other{{count} found}}",
+  "@assistantLookedUpPdfs": {"placeholders": {"query": {"type": "String"}, "count": {"type": "int"}}},
+  "assistantLookedUpPage": "Read a page of a PDF",
+  "assistantLookedUpNoPage": "Looked for a page of a PDF, couldn't read it",
+  "assistantShownImage": "Was shown an image you approved",
+  "assistantNotShownImage": "Was not shown an image",
+  "assistantShownPage": "Was shown a page you approved",
+  "assistantNotShownPage": "Was not shown a page",
+  "assistantImageAskCard": "{name} asks to see image {number} of the card “{title}”.",
+  "@assistantImageAskCard": {"description": "The model asks for an image; the person approves each (D12).", "placeholders": {"name": {"type": "String"}, "number": {"type": "int"}, "title": {"type": "String"}}},
+  "assistantImageAskPage": "{name} asks to see page {page} of “{title}” as a picture.",
+  "@assistantImageAskPage": {"placeholders": {"name": {"type": "String"}, "page": {"type": "int"}, "title": {"type": "String"}}},
+  "assistantImageShow": "Show it",
+  "assistantImageDontShow": "Don't show",
   "assistantPrivateTitle": "{count, plural, =1{Send a private studyset to {name}?} other{Send private studysets to {name}?}}",
   "@assistantPrivateTitle": {"description": "The warning before a private studyset's content goes to a remote model (ADR 0021, D9).", "placeholders": {"count": {"type": "int"}, "name": {"type": "String"}}},
   "assistantPrivateGranted": "{count, plural, =1{It is end-to-end encrypted, so that not even {instance} can read it. What {name} looks up in it, or what you chose of it, passes through {instance}, which keeps none of it, to {host}, which reads it under the provider's terms.} other{They are end-to-end encrypted, so that not even {instance} can read them. What {name} looks up in them, or what you chose of them, passes through {instance}, which keeps none of it, to {host}, which reads it under the provider's terms.}}",

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations.dart

@@ -10701,6 +10701,12 @@ abstract class AppLocalizations {
   /// **'Studyset: {title}'**
   String assistantChipStudyset(String title);
 
+  /// A chip sending an image on the card (ADR 0021, D12).
+  ///
+  /// In en, this message translates to:
+  /// **'Image {number}'**
+  String assistantChipImage(int number);
+
   /// No description provided for @assistantHintWeb.
   ///
   /// In en, this message translates to:
@@ -10965,6 +10971,78 @@ abstract class AppLocalizations {
   /// **'Looked for a note, found none'**
   String get assistantLookedUpNoNote;
 
+  /// No description provided for @assistantListedPdfs.
+  ///
+  /// In en, this message translates to:
+  /// **'Listed {count, plural, =0{no PDFs} =1{1 PDF} other{{count} PDFs}}'**
+  String assistantListedPdfs(int count);
+
+  /// No description provided for @assistantLookedUpPdfs.
+  ///
+  /// In en, this message translates to:
+  /// **'Looked for “{query}” in PDFs: {count, plural, =0{none found} =1{1 found} other{{count} found}}'**
+  String assistantLookedUpPdfs(String query, int count);
+
+  /// No description provided for @assistantLookedUpPage.
+  ///
+  /// In en, this message translates to:
+  /// **'Read a page of a PDF'**
+  String get assistantLookedUpPage;
+
+  /// No description provided for @assistantLookedUpNoPage.
+  ///
+  /// In en, this message translates to:
+  /// **'Looked for a page of a PDF, couldn\'t read it'**
+  String get assistantLookedUpNoPage;
+
+  /// No description provided for @assistantShownImage.
+  ///
+  /// In en, this message translates to:
+  /// **'Was shown an image you approved'**
+  String get assistantShownImage;
+
+  /// No description provided for @assistantNotShownImage.
+  ///
+  /// In en, this message translates to:
+  /// **'Was not shown an image'**
+  String get assistantNotShownImage;
+
+  /// No description provided for @assistantShownPage.
+  ///
+  /// In en, this message translates to:
+  /// **'Was shown a page you approved'**
+  String get assistantShownPage;
+
+  /// No description provided for @assistantNotShownPage.
+  ///
+  /// In en, this message translates to:
+  /// **'Was not shown a page'**
+  String get assistantNotShownPage;
+
+  /// The model asks for an image; the person approves each (D12).
+  ///
+  /// In en, this message translates to:
+  /// **'{name} asks to see image {number} of the card “{title}”.'**
+  String assistantImageAskCard(String name, int number, String title);
+
+  /// No description provided for @assistantImageAskPage.
+  ///
+  /// In en, this message translates to:
+  /// **'{name} asks to see page {page} of “{title}” as a picture.'**
+  String assistantImageAskPage(String name, int page, String title);
+
+  /// No description provided for @assistantImageShow.
+  ///
+  /// In en, this message translates to:
+  /// **'Show it'**
+  String get assistantImageShow;
+
+  /// No description provided for @assistantImageDontShow.
+  ///
+  /// In en, this message translates to:
+  /// **'Don\'t show'**
+  String get assistantImageDontShow;
+
   /// The warning before a private studyset's content goes to a remote model (ADR 0021, D9).
   ///
   /// In en, this message translates to:

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations_de.dart

@@ -6707,6 +6707,11 @@ class AppLocalizationsDe extends AppLocalizations {
     return 'Lernset: $title';
   }
 
+  @override
+  String assistantChipImage(int number) {
+    return 'Bild $number';
+  }
+
   @override
   String get assistantHintWeb => 'Im Web suchen…';
 
@@ -6876,6 +6881,67 @@ class AppLocalizationsDe extends AppLocalizations {
   @override
   String get assistantLookedUpNoNote => 'Eine Notiz gesucht, keine gefunden';
 
+  @override
+  String assistantListedPdfs(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count PDFs',
+      one: '1 PDF',
+      zero: 'Keine PDFs',
+    );
+    return '$_temp0 aufgelistet';
+  }
+
+  @override
+  String assistantLookedUpPdfs(String query, int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count gefunden',
+      one: '1 gefunden',
+      zero: 'keine gefunden',
+    );
+    return 'PDFs nach „$query“ durchsucht: $_temp0';
+  }
+
+  @override
+  String get assistantLookedUpPage => 'Eine Seite einer PDF gelesen';
+
+  @override
+  String get assistantLookedUpNoPage =>
+      'Eine Seite einer PDF gesucht, nicht lesbar';
+
+  @override
+  String get assistantShownImage =>
+      'Hat ein Bild gesehen, das du freigegeben hast';
+
+  @override
+  String get assistantNotShownImage => 'Hat ein Bild nicht gesehen';
+
+  @override
+  String get assistantShownPage =>
+      'Hat eine Seite gesehen, die du freigegeben hast';
+
+  @override
+  String get assistantNotShownPage => 'Hat eine Seite nicht gesehen';
+
+  @override
+  String assistantImageAskCard(String name, int number, String title) {
+    return '$name möchte Bild $number der Karte „$title“ sehen.';
+  }
+
+  @override
+  String assistantImageAskPage(String name, int page, String title) {
+    return '$name möchte Seite $page von „$title“ als Bild sehen.';
+  }
+
+  @override
+  String get assistantImageShow => 'Zeigen';
+
+  @override
+  String get assistantImageDontShow => 'Nicht zeigen';
+
   @override
   String assistantPrivateTitle(int count, String name) {
     String _temp0 = intl.Intl.pluralLogic(

apps/learn/halkyon_learn_flutter/lib/l10n/app_localizations_en.dart

@@ -6643,6 +6643,11 @@ class AppLocalizationsEn extends AppLocalizations {
     return 'Studyset: $title';
   }
 
+  @override
+  String assistantChipImage(int number) {
+    return 'Image $number';
+  }
+
   @override
   String get assistantHintWeb => 'Search the web…';
 
@@ -6812,6 +6817,65 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get assistantLookedUpNoNote => 'Looked for a note, found none';
 
+  @override
+  String assistantListedPdfs(int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count PDFs',
+      one: '1 PDF',
+      zero: 'no PDFs',
+    );
+    return 'Listed $_temp0';
+  }
+
+  @override
+  String assistantLookedUpPdfs(String query, int count) {
+    String _temp0 = intl.Intl.pluralLogic(
+      count,
+      locale: localeName,
+      other: '$count found',
+      one: '1 found',
+      zero: 'none found',
+    );
+    return 'Looked for “$query” in PDFs: $_temp0';
+  }
+
+  @override
+  String get assistantLookedUpPage => 'Read a page of a PDF';
+
+  @override
+  String get assistantLookedUpNoPage =>
+      'Looked for a page of a PDF, couldn\'t read it';
+
+  @override
+  String get assistantShownImage => 'Was shown an image you approved';
+
+  @override
+  String get assistantNotShownImage => 'Was not shown an image';
+
+  @override
+  String get assistantShownPage => 'Was shown a page you approved';
+
+  @override
+  String get assistantNotShownPage => 'Was not shown a page';
+
+  @override
+  String assistantImageAskCard(String name, int number, String title) {
+    return '$name asks to see image $number of the card “$title”.';
+  }
+
+  @override
+  String assistantImageAskPage(String name, int page, String title) {
+    return '$name asks to see page $page of “$title” as a picture.';
+  }
+
+  @override
+  String get assistantImageShow => 'Show it';
+
+  @override
+  String get assistantImageDontShow => 'Don\'t show';
+
   @override
   String assistantPrivateTitle(int count, String name) {
     String _temp0 = intl.Intl.pluralLogic(