[Icons] Add an Informational semantic color family

Face-down play and the exile zone are states that are neither a gain nor a
loss, and the pre-#7595 art painted them blue (arrow_right_blue). #7595 dropped
that hue, and the icon engine has had only Positive and Negative since, so both
states fall back to neutral ink.

Add the family with the same three-level ladder the other semantic roles use:
authored roles per theme, scheme defaults otherwise, an emphasis mapping, the
palette-editor rows and the generator seed. The defaults clear the 4.5:1 label
floor on both schemes and the ladder's saturation ordering; the existing
emphasis, hue and preview tests now cover the new family. Preview sheets that
name roles resolve an unauthored one through the same default the client
paints.

cockatrice/src/interface/palette_editor/palette_generator.cpp

@@ -178,9 +178,12 @@ PaletteConfig fromAccent(const QColor &accent, int intensity, const QString &sch
     cfg.appColors[AppColor::IconStrong] = ThemeIconInk::forEmphasis(iconInk, iconSurface, IconEmphasis::Primary);
     cfg.appColors[AppColor::IconSoft] = ThemeIconInk::forEmphasis(iconInk, iconSurface, IconEmphasis::Quiet);
     // Semantic roles stay independent of the accent: a generated palette must
-    // still paint add/ready green and remove/not-ready red.
-    for (const AppColor::Role role : {AppColor::Positive, AppColor::PositiveStrong, AppColor::PositiveSoft,
-                                      AppColor::Negative, AppColor::NegativeStrong, AppColor::NegativeSoft}) {
+    // still paint add/ready green, remove/not-ready red, and the neutral
+    // information state blue.
+    for (const AppColor::Role role :
+         {AppColor::Positive, AppColor::PositiveStrong, AppColor::PositiveSoft, AppColor::Negative,
+          AppColor::NegativeStrong, AppColor::NegativeSoft, AppColor::Informational, AppColor::InformationalStrong,
+          AppColor::InformationalSoft}) {
         cfg.appColors[role] = defaultAppColor(role, dark);
     }
 

cockatrice/src/interface/palette_editor/palette_grid_widget.cpp

@@ -78,6 +78,11 @@ static const QMap<AppColor::Role, const char *> APP_ROLE_DESCRIPTIONS = {
      QT_TRANSLATE_NOOP("PaletteGridWidget", "Negative state and removal actions (not ready, remove, decrement)")},
     {AppColor::NegativeStrong, QT_TRANSLATE_NOOP("PaletteGridWidget", "Negative state at primary emphasis")},
     {AppColor::NegativeSoft, QT_TRANSLATE_NOOP("PaletteGridWidget", "Negative state at quiet emphasis")},
+    {AppColor::Informational,
+     QT_TRANSLATE_NOOP("PaletteGridWidget",
+                       "Informational state that is neither a gain nor a loss (face-down, exile)")},
+    {AppColor::InformationalStrong, QT_TRANSLATE_NOOP("PaletteGridWidget", "Informational state at primary emphasis")},
+    {AppColor::InformationalSoft, QT_TRANSLATE_NOOP("PaletteGridWidget", "Informational state at quiet emphasis")},
 };
 
 PaletteGridWidget::PaletteGridWidget(QWidget *parent) : QWidget(parent)

cockatrice/src/interface/theme_config.cpp

@@ -482,6 +482,15 @@ QColor defaultAppColor(AppColor::Role role, bool dark)
             return QColor(dark ? QStringLiteral("#ff8378") : QStringLiteral("#da0b00"));
         case AppColor::NegativeSoft:
             return QColor(dark ? QStringLiteral("#c79e9b") : QStringLiteral("#935f5c"));
+        // Informational is the third semantic family: a state that is neither a
+        // gain nor a loss (a face-down play, the exile zone). It carries the
+        // same three-level ladder so its emphasis is authored, not computed.
+        case AppColor::Informational:
+            return QColor(dark ? QStringLiteral("#7aa9f2") : QStringLiteral("#1c64c4"));
+        case AppColor::InformationalStrong:
+            return QColor(dark ? QStringLiteral("#69aeff") : QStringLiteral("#0a4fb5"));
+        case AppColor::InformationalSoft:
+            return QColor(dark ? QStringLiteral("#9db2cd") : QStringLiteral("#526a8a"));
     }
 
     return {};

cockatrice/src/interface/theme_config.h

@@ -15,11 +15,11 @@
 // beyond what Qt's palette can express.
 //
 // The icon families carry one role per emphasis level. Icon is the neutral
-// glyph ink; IconStrong and IconSoft are its primary and quiet levels. Positive
-// and Negative follow the same pattern, so an emphasis never has to be computed
-// from a hue at paint time: the theme authors all three levels. Naming a variant
-// explicitly (`IconStrong`) pins that level; naming the family (`Icon`) lets the
-// caller's emphasis choose.
+// glyph ink; IconStrong and IconSoft are its primary and quiet levels. Positive,
+// Negative and Informational follow the same pattern, so an emphasis never has
+// to be computed from a hue at paint time: the theme authors all three levels.
+// Naming a variant explicitly (`IconStrong`) pins that level; naming the family
+// (`Icon`) lets the caller's emphasis choose.
 namespace AppColor
 {
 Q_NAMESPACE
@@ -36,6 +36,9 @@ enum Role
     Negative,
     NegativeStrong,
     NegativeSoft,
+    Informational,
+    InformationalStrong,
+    InformationalSoft,
 };
 Q_ENUM_NS(Role)
 } // namespace AppColor

cockatrice/src/interface/theme_icon.cpp

@@ -54,6 +54,10 @@ AppColor::Role emphasisRole(AppColor::Role role, IconEmphasis emphasis)
             return emphasis == IconEmphasis::Primary ? AppColor::NegativeStrong
                    : emphasis == IconEmphasis::Quiet ? AppColor::NegativeSoft
                                                      : AppColor::Negative;
+        case AppColor::Informational:
+            return emphasis == IconEmphasis::Primary ? AppColor::InformationalStrong
+                   : emphasis == IconEmphasis::Quiet ? AppColor::InformationalSoft
+                                                     : AppColor::Informational;
         default:
             return role;
     }

cockatrice/src/interface/theme_manager.cpp

@@ -683,6 +683,9 @@ QColor ThemeManager::appColor(AppColor::Role role) const
         case AppColor::Negative:
         case AppColor::NegativeStrong:
         case AppColor::NegativeSoft:
+        case AppColor::Informational:
+        case AppColor::InformationalStrong:
+        case AppColor::InformationalSoft:
             // Semantic colors are independent of the accent: a missing role must
             // not silently paint "remove" in the theme's highlight color.
             return defaultAppColor(role, isDarkModeActive());