fix: wire through silent restart clear resume state with sdk (#2033)

## Summary

After a silent reboot, there was a small window where the esp32 would
listen for button presses but the full refresh would hold the event
loop. This gave a UX experience where the silent reboot had completed to
the home screen, a user taps select (at any time during the process),
and they find themselves unexpectedly in a book.

## Additional Context

This must land after
https://github.com/crosspoint-reader/community-sdk/pull/11 and will need
the submodule SHA changes included in. 

---

### AI Usage

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please be transparent about their usage as it
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Did you use AI tools to help write this code? partially

lib/hal/HalDisplay.cpp

@@ -18,14 +18,18 @@ void HalDisplay::begin(bool seamless) {
 
   einkDisplay.begin();
 
+  if (seamless) {
+    // Defuse the SDK's X3 _x3InitialFullSyncsRemaining counter (no-op on X4)
+    // so the first paint isn't promoted to FULL (~770ms). Skips the wakeup-
+    // gated requestResync() below for the same reason.
+    einkDisplay.skipInitialResync();
+    return;
+  }
   // Request resync after specific wakeup events to ensure clean display state.
-  // Skip when seamless=true so the current screen content is preserved.
-  if (!seamless) {
-    const auto wakeupReason = gpio.getWakeupReason();
-    if (wakeupReason == HalGPIO::WakeupReason::PowerButton || wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
-        wakeupReason == HalGPIO::WakeupReason::Other) {
-      einkDisplay.requestResync();
-    }
+  const auto wakeupReason = gpio.getWakeupReason();
+  if (wakeupReason == HalGPIO::WakeupReason::PowerButton || wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
+      wakeupReason == HalGPIO::WakeupReason::Other) {
+    einkDisplay.requestResync();
   }
 }
 

lib/hal/HalDisplay.h

@@ -17,7 +17,12 @@ class HalDisplay {
     FAST_REFRESH   // Fast refresh using custom LUT
   };
 
-  // Initialize the display hardware and driver
+  // Pass seamless=true on any path where the panel already shows the
+  // content it should after begin() returns (silent reboot's popup,
+  // sleep-wake with a restored buffer). Skips the wakeup-gated
+  // requestResync() and defuses the SDK's X3 _x3InitialFullSyncsRemaining
+  // counter; otherwise the first two paints get promoted to FULL
+  // (~770ms each on X3).
   void begin(bool seamless = false);
 
   // Display dimensions

src/main.cpp

@@ -146,6 +146,11 @@ void silentRestart() {
   silentRebootTarget = SILENT_REBOOT_TARGET_HOME;
   silentRebootMagic = SILENT_REBOOT_MAGIC;
   LOG_DBG("MAIN", "Silent restart (target=home)");
+  // E-ink retains the previous frame until Home's first paint lands (~2-3s).
+  // Without an overlay, users don't see the reboot and fire input through to
+  // Home. Select on the default selectorIndex=0 then opens the most-recent
+  // book, looking like a trampoline back to the reader they just exited.
+  GUI.drawPopup(renderer, tr(STR_LOADING_POPUP));
   delay(50);
   ESP.restart();
 }
@@ -154,6 +159,7 @@ void silentRestartToReader() {
   silentRebootTarget = SILENT_REBOOT_TARGET_READER;
   silentRebootMagic = SILENT_REBOOT_MAGIC;
   LOG_DBG("MAIN", "Silent restart (target=reader)");
+  GUI.drawPopup(renderer, tr(STR_LOADING_POPUP));
   delay(50);
   ESP.restart();
 }
@@ -336,7 +342,7 @@ void setup() {
   // We need 6 open files concurrently when parsing a new chapter
   if (!Storage.begin()) {
     LOG_ERR("MAIN", "SD card initialization failed");
-    setupDisplayAndFonts();
+    setupDisplayAndFonts(isSilentReboot);
     activityManager.goToFullScreenMessage("SD card error", EpdFontFamily::BOLD);
     return;
   }
@@ -393,10 +399,11 @@ void setup() {
   // First serial output only here to avoid timing inconsistencies for power button press duration verification
   LOG_DBG("MAIN", "Starting CrossPoint version " CROSSPOINT_VERSION);
 
-  setupDisplayAndFonts(/*seamless=*/!APP_STATE.showBootScreen);
+  setupDisplayAndFonts(isSilentReboot || /*seamless=*/!APP_STATE.showBootScreen);
 
-  // First paint after silent reboot is HALF_REFRESH (SDK forces it after begin()'s
-  // panel reset); subsequent paints FAST.
+  // Silent reboot suppresses the boot splash and the X3 initial-full-sync
+  // arming (see HalDisplay::begin), so the first Home paint is FAST_REFRESH
+  // (~500ms) and input dispatches against the visible menu.
   if (!isSilentReboot) {
     if (APP_STATE.showBootScreen) {
       activityManager.goToBoot();
@@ -443,6 +450,23 @@ void setup() {
     activityManager.goToReader(path);
   }
 
+  if (isSilentReboot) {
+    // Block until the first paint physically completes. refreshDisplay()
+    // waits on the panel BUSY pin so when this returns the user can see the
+    // new activity. Without the wait, an edge captured by gpio.update()
+    // during boot dispatches against an invisible Home and the default
+    // selectorIndex=0 opens the most-recent book.
+    activityManager.requestUpdateAndWait();
+    // Absorb any button held at this point into currentState as a non-edge:
+    // two gpio.update() calls separated by > InputManager's 5ms debounce
+    // transition the held bit through lastDebounceTime into currentState
+    // without setting pressedEvents, so the first loop()'s own gpio.update()
+    // sees state == currentState and emits nothing.
+    gpio.update();
+    delay(10);
+    gpio.update();
+  }
+
   // Ensure we're not still holding the power button before leaving setup
   waitForPowerRelease();
   allowSleepAt = millis() + 2000;