feat: silent pre-indexing with configurable status bar indicator

Port PR #979's silent pre-indexing and add an Indexing Display setting
(Popup / Status Bar Text / Status Bar Icon) so users can choose how
indexing feedback is shown.

Silent pre-indexing runs on text-only penultimate pages when a status
bar option is selected, with a standard requestUpdate to clear the
indicator. Image pages skip silent indexing to avoid e-ink grayscale
pipeline conflicts; the normal popup handles those transitions. Direct
chapter jumps always show the original small popup regardless of setting.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/I18n/I18nKeys.h

@@ -390,6 +390,10 @@ enum class StrId : uint16_t {
   STR_TZ_HAWAII,
   STR_TZ_CUSTOM,
   STR_SET_UTC_OFFSET,
+  STR_INDEXING_DISPLAY,
+  STR_INDEXING_POPUP,
+  STR_INDEXING_STATUS_TEXT,
+  STR_INDEXING_STATUS_ICON,
   // Sentinel - must be last
   _COUNT
 };

lib/I18n/translations/czech.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Zobrazení indexování"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Text stavového řádku"
+STR_INDEXING_STATUS_ICON: "Ikona stavového řádku"

lib/I18n/translations/english.yaml

@@ -356,3 +356,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Indexing Display"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Status Bar Text"
+STR_INDEXING_STATUS_ICON: "Status Bar Icon"

lib/I18n/translations/french.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Affichage indexation"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Texte barre d'état"
+STR_INDEXING_STATUS_ICON: "Icône barre d'état"

lib/I18n/translations/german.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Indexierungsanzeige"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Statusleistentext"
+STR_INDEXING_STATUS_ICON: "Statusleistensymbol"

lib/I18n/translations/portuguese.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Exibição de indexação"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Texto da barra"
+STR_INDEXING_STATUS_ICON: "Ícone da barra"

lib/I18n/translations/russian.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Отображение индексации"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Текст в строке"
+STR_INDEXING_STATUS_ICON: "Иконка в строке"

lib/I18n/translations/spanish.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Mostrar indexación"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Texto barra estado"
+STR_INDEXING_STATUS_ICON: "Icono barra estado"

lib/I18n/translations/swedish.yaml

@@ -335,3 +335,7 @@ STR_TZ_ALASKA: "Alaska"
 STR_TZ_HAWAII: "Hawaii"
 STR_TZ_CUSTOM: "Custom"
 STR_SET_UTC_OFFSET: "Set UTC Offset"
+STR_INDEXING_DISPLAY: "Indexeringsvisning"
+STR_INDEXING_POPUP: "Popup"
+STR_INDEXING_STATUS_TEXT: "Statusfältstext"
+STR_INDEXING_STATUS_ICON: "Statusfältsikon"