feat(app): tag, edit, delete and swipe cards while studying, with tidier session sheets

- Above every studied card (but a matching one): the PDF it came from,
  its tags on one line ("+2 tags" for the rest) or "Add tags", and a
  menu to tag, edit or delete it; the session follows (an edited card
  shows as saved, a deleted one leaves the round).
- On phones, a front/back or vocabulary card swiped right is rated
  Good, left Bad; it tilts over the colour it heads for, and springs
  back when let go early.
- The session's settings: "Settings", a 48 dp Save that warns mid-round
  ("Heads up!"), steppers in an outlined box ("20 / day", "5 / 50"),
  the order in an outlined dropdown, the chosen tags with the rest
  behind "Filter by tags" / "+3 more".
- A studyset's study options: Save above Reset to defaults, the
  description small, reviews a day in steps of 25.
- One stepper look everywhere (study, Pomodoro profiles), its buttons
  "Decrease" and "Increase".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

halkyon_learn_flutter/lib/l10n/app_localizations.dart

@@ -2008,16 +2008,10 @@ abstract class AppLocalizations {
   /// **'Filter by tags'**
   String get studySettingsFilterByTags;
 
-  /// No description provided for @studySettingsFilterHint.
-  ///
-  /// In en, this message translates to:
-  /// **'Study only the flashcards with any of the tags chosen.'**
-  String get studySettingsFilterHint;
-
   /// No description provided for @studySettingsNoTags.
   ///
   /// In en, this message translates to:
-  /// **'No tags yet. Add tags to your flashcards to filter them here.'**
+  /// **'No content tags yet. Add tags to your cards to filter them here.'**
   String get studySettingsNoTags;
 
   /// No description provided for @studySettingsReset.
@@ -2032,6 +2026,36 @@ abstract class AppLocalizations {
   /// **'Save'**
   String get studySettingsSave;
 
+  /// No description provided for @studySettingsHeadsUpTitle.
+  ///
+  /// In en, this message translates to:
+  /// **'Heads up!'**
+  String get studySettingsHeadsUpTitle;
+
+  /// No description provided for @studySettingsHeadsUpBody.
+  ///
+  /// In en, this message translates to:
+  /// **'The changes you’ve made will reload the session, and you’ll lose your current progress.'**
+  String get studySettingsHeadsUpBody;
+
+  /// No description provided for @studySettingsApplyChanges.
+  ///
+  /// In en, this message translates to:
+  /// **'Apply changes'**
+  String get studySettingsApplyChanges;
+
+  /// No description provided for @studySettingsPerDay.
+  ///
+  /// In en, this message translates to:
+  /// **' / day'**
+  String get studySettingsPerDay;
+
+  /// No description provided for @studySettingsMoreTags.
+  ///
+  /// In en, this message translates to:
+  /// **'+{count} more'**
+  String studySettingsMoreTags(int count);
+
   /// No description provided for @cardTagsLabel.
   ///
   /// In en, this message translates to:
@@ -2050,6 +2074,12 @@ abstract class AppLocalizations {
   /// **'Edit tags'**
   String get cardTagsEdit;
 
+  /// No description provided for @tagChipsOverflow.
+  ///
+  /// In en, this message translates to:
+  /// **'+{count, plural, =1{1 tag} other{{count} tags}}'**
+  String tagChipsOverflow(int count);
+
   /// No description provided for @cardFilterTooltip.
   ///
   /// In en, this message translates to:
@@ -2968,12 +2998,6 @@ abstract class AppLocalizations {
   /// **'Reviews per day'**
   String get studyOptionsReviewsPerDay;
 
-  /// No description provided for @studyOptionsReviewsPerDayHint.
-  ///
-  /// In en, this message translates to:
-  /// **'Cards in their learning steps come anyway.'**
-  String get studyOptionsReviewsPerDayHint;
-
   /// No description provided for @studyOptionsOrder.
   ///
   /// In en, this message translates to:
@@ -3067,13 +3091,13 @@ abstract class AppLocalizations {
   /// No description provided for @studyFewer.
   ///
   /// In en, this message translates to:
-  /// **'Fewer'**
+  /// **'Decrease'**
   String get studyFewer;
 
   /// No description provided for @studyMore.
   ///
   /// In en, this message translates to:
-  /// **'More'**
+  /// **'Increase'**
   String get studyMore;
 
   /// No description provided for @studysetMenuReset.