feat: Extend high contrast mode to entire UI

- Add global high contrast mode flag in BitmapHelpers
- Modify quantization thresholds for high contrast rendering
- Update ditherer classes (Atkinson, Floyd-Steinberg) for contrast mode
- Add displayContrast setting with persistence
- Add "High Contrast" toggle in display settings
- Apply high contrast mode on startup from saved settings

src/activities/settings/CategorySettingsActivity.cpp

@@ -1,5 +1,6 @@
 #include "CategorySettingsActivity.h"
 
+#include <BitmapHelpers.h>
 #include <GfxRenderer.h>
 #include <HardwareSerial.h>
 
@@ -115,6 +116,11 @@ void CategorySettingsActivity::toggleCurrentSetting() {
     // Toggle the boolean value using the member pointer
     const bool currentValue = SETTINGS.*(setting.valuePtr);
     SETTINGS.*(setting.valuePtr) = !currentValue;
+
+    // Handle side effects for specific settings
+    if (setting.valuePtr == &CrossPointSettings::displayContrast) {
+      setHighContrastMode(SETTINGS.displayContrast == 1);
+    }
   } else if (setting.type == SettingType::ENUM && setting.valuePtr != nullptr) {
     const uint8_t currentValue = SETTINGS.*(setting.valuePtr);
     SETTINGS.*(setting.valuePtr) = (currentValue + 1) % static_cast<uint8_t>(setting.enumValues.size());

src/activities/settings/SettingsActivity.cpp

@@ -19,6 +19,7 @@ const SettingInfo displaySettings[displaySettingsCount] = {
     SettingInfo::Enum("Sleep Screen Cover Mode", &CrossPointSettings::sleepScreenCoverMode, {"Fit", "Crop", "Actual"}),
     SettingInfo::Enum("Sleep Screen Cover Filter", &CrossPointSettings::sleepScreenCoverFilter,
                       {"None", "Contrast", "Inverted"}),
+    SettingInfo::Toggle("High Contrast", &CrossPointSettings::displayContrast),
     SettingInfo::Enum("Status Bar", &CrossPointSettings::statusBar,
                       {"None", "No Progress", "Full w/ Percentage", "Full w/ Progress Bar", "Progress Bar"}),
     SettingInfo::Enum("Hide Battery %", &CrossPointSettings::hideBatteryPercentage, {"Never", "In Reader", "Always"}),