feat: add Xteink X3 hardware support

Adds HAL-level support for the Xteink X3 (SSD1677 controller, 792x528
display). Includes device detection, display initialization, button
mapping, power management, and theme adjustments for the X3 form factor.

lib/hal/HalDisplay.cpp

@@ -1,13 +1,30 @@
 #include <HalDisplay.h>
 #include <HalGPIO.h>
 
+// Global HalDisplay instance
+HalDisplay display;
+
 #define SD_SPI_MISO 7
 
 HalDisplay::HalDisplay() : einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY) {}
 
 HalDisplay::~HalDisplay() {}
 
-void HalDisplay::begin() { einkDisplay.begin(); }
+void HalDisplay::begin() {
+  // Set X3-specific panel mode before initializing.
+  if (gpio.deviceIsX3()) {
+    einkDisplay.setDisplayX3();
+  }
+
+  einkDisplay.begin();
+
+  // Request resync after specific wakeup events to ensure clean display state
+  const auto wakeupReason = gpio.getWakeupReason();
+  if (wakeupReason == HalGPIO::WakeupReason::PowerButton || wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
+      wakeupReason == HalGPIO::WakeupReason::Other) {
+    einkDisplay.requestResync();
+  }
+}
 
 void HalDisplay::clearScreen(uint8_t color) const { einkDisplay.clearScreen(color); }
 
@@ -34,10 +51,18 @@ EInkDisplay::RefreshMode convertRefreshMode(HalDisplay::RefreshMode mode) {
 }
 
 void HalDisplay::displayBuffer(HalDisplay::RefreshMode mode, bool turnOffScreen) {
+  if (gpio.deviceIsX3() && mode == RefreshMode::HALF_REFRESH) {
+    einkDisplay.requestResync(1);
+  }
+
   einkDisplay.displayBuffer(convertRefreshMode(mode), turnOffScreen);
 }
 
 void HalDisplay::refreshDisplay(HalDisplay::RefreshMode mode, bool turnOffScreen) {
+  if (gpio.deviceIsX3() && mode == RefreshMode::HALF_REFRESH) {
+    einkDisplay.requestResync(1);
+  }
+
   einkDisplay.refreshDisplay(convertRefreshMode(mode), turnOffScreen);
 }
 
@@ -56,3 +81,11 @@ void HalDisplay::copyGrayscaleMsbBuffers(const uint8_t* msbBuffer) { einkDisplay
 void HalDisplay::cleanupGrayscaleBuffers(const uint8_t* bwBuffer) { einkDisplay.cleanupGrayscaleBuffers(bwBuffer); }
 
 void HalDisplay::displayGrayBuffer(bool turnOffScreen) { einkDisplay.displayGrayBuffer(turnOffScreen); }
+
+uint16_t HalDisplay::getDisplayWidth() const { return einkDisplay.getDisplayWidth(); }
+
+uint16_t HalDisplay::getDisplayHeight() const { return einkDisplay.getDisplayHeight(); }
+
+uint16_t HalDisplay::getDisplayWidthBytes() const { return einkDisplay.getDisplayWidthBytes(); }
+
+uint32_t HalDisplay::getBufferSize() const { return einkDisplay.getBufferSize(); }