merge upstream/master: logging pragma, screenshot retrieval, nbsp fix

Merge 3 upstream commits into mod/master:
- feat: Allow screenshot retrieval from device (#820)
- feat: Add central logging pragma (#843)
- fix: Account for nbsp character as non-breaking space (#757)

Conflict resolution:
- src/main.cpp: kept mod's HalPowerManager + upstream's Logging/screenshot
- SleepActivity.cpp: kept mod's letterbox fill rework, applied LOG_* pattern

Additional changes for logging compatibility:
- Converted remaining Serial.printf calls in mod files to LOG_* macros
  (HalPowerManager, BookSettings, BookmarkStore, GfxRenderer)
- Added ENABLE_SERIAL_LOG and LOG_LEVEL=2 to [env:mod] build flags

Co-authored-by: Cursor <cursoragent@cursor.com>

src/main.cpp

@@ -5,6 +5,7 @@
 #include <HalGPIO.h>
 #include <HalPowerManager.h>
 #include <HalStorage.h>
+#include <Logging.h>
 #include <SPI.h>
 #include <builtinFonts/all.h>
 
@@ -203,8 +204,8 @@ void enterDeepSleep() {
   enterNewActivity(new SleepActivity(renderer, mappedInputManager));
 
   display.deepSleep();
-  Serial.printf("[%lu] [   ] Power button press calibration value: %lu ms\n", millis(), t2 - t1);
-  Serial.printf("[%lu] [   ] Entering deep sleep.\n", millis());
+  LOG_DBG("MAIN", "Power button press calibration value: %lu ms", t2 - t1);
+  LOG_DBG("MAIN", "Entering deep sleep");
 
   powerManager.startDeepSleep(gpio);
 }
@@ -257,7 +258,7 @@ void onGoHome() {
 void setupDisplayAndFonts() {
   display.begin();
   renderer.begin();
-  Serial.printf("[%lu] [   ] Display initialized\n", millis());
+  LOG_DBG("MAIN", "Display initialized");
   renderer.insertFont(BOOKERLY_14_FONT_ID, bookerly14FontFamily);
 #ifndef OMIT_FONTS
   renderer.insertFont(BOOKERLY_12_FONT_ID, bookerly12FontFamily);
@@ -276,7 +277,7 @@ void setupDisplayAndFonts() {
   renderer.insertFont(UI_10_FONT_ID, ui10FontFamily);
   renderer.insertFont(UI_12_FONT_ID, ui12FontFamily);
   renderer.insertFont(SMALL_FONT_ID, smallFontFamily);
-  Serial.printf("[%lu] [   ] Fonts setup\n", millis());
+  LOG_DBG("MAIN", "Fonts setup");
 }
 
 void setup() {
@@ -298,7 +299,7 @@ void setup() {
   // SD Card Initialization
   // We need 6 open files concurrently when parsing a new chapter
   if (!Storage.begin()) {
-    Serial.printf("[%lu] [   ] SD card initialization failed\n", millis());
+    LOG_ERR("MAIN", "SD card initialization failed");
     setupDisplayAndFonts();
     exitActivity();
     enterNewActivity(new FullScreenMessageActivity(renderer, mappedInputManager, "SD card error", EpdFontFamily::BOLD));
@@ -313,12 +314,12 @@ void setup() {
   switch (gpio.getWakeupReason()) {
     case HalGPIO::WakeupReason::PowerButton:
       // For normal wakeups, verify power button press duration
-      Serial.printf("[%lu] [   ] Verifying power button press duration\n", millis());
+      LOG_DBG("MAIN", "Verifying power button press duration");
       verifyPowerButtonDuration();
       break;
     case HalGPIO::WakeupReason::AfterUSBPower:
       // If USB power caused a cold boot, go back to sleep
-      Serial.printf("[%lu] [   ] Wakeup reason: After USB Power\n", millis());
+      LOG_DBG("MAIN", "Wakeup reason: After USB Power");
       powerManager.startDeepSleep(gpio);
       break;
     case HalGPIO::WakeupReason::AfterFlash:
@@ -329,7 +330,7 @@ void setup() {
   }
 
   // First serial output only here to avoid timing inconsistencies for power button press duration verification
-  Serial.printf("[%lu] [   ] Starting CrossPoint version " CROSSPOINT_VERSION "\n", millis());
+  LOG_DBG("MAIN", "Starting CrossPoint version " CROSSPOINT_VERSION);
 
   setupDisplayAndFonts();
 
@@ -367,11 +368,27 @@ void loop() {
   renderer.setFadingFix(SETTINGS.fadingFix);
 
   if (Serial && millis() - lastMemPrint >= 10000) {
-    Serial.printf("[%lu] [MEM] Free: %d bytes, Total: %d bytes, Min Free: %d bytes\n", millis(), ESP.getFreeHeap(),
-                  ESP.getHeapSize(), ESP.getMinFreeHeap());
+    LOG_INF("MEM", "Free: %d bytes, Total: %d bytes, Min Free: %d bytes", ESP.getFreeHeap(), ESP.getHeapSize(),
+            ESP.getMinFreeHeap());
     lastMemPrint = millis();
   }
 
+  // Handle incoming serial commands,
+  // nb: we use logSerial from logging to avoid deprecation warnings
+  if (logSerial.available() > 0) {
+    String line = logSerial.readStringUntil('\n');
+    if (line.startsWith("CMD:")) {
+      String cmd = line.substring(4);
+      cmd.trim();
+      if (cmd == "SCREENSHOT") {
+        logSerial.printf("SCREENSHOT_START:%d\n", HalDisplay::BUFFER_SIZE);
+        uint8_t* buf = display.getFrameBuffer();
+        logSerial.write(buf, HalDisplay::BUFFER_SIZE);
+        logSerial.printf("SCREENSHOT_END\n");
+      }
+    }
+  }
+
   // Check for any user activity (button press or release) or active background work
   static unsigned long lastActivityTime = millis();
   if (gpio.wasAnyPressed() || gpio.wasAnyReleased() || (currentActivity && currentActivity->preventAutoSleep())) {
@@ -381,7 +398,7 @@ void loop() {
 
   const unsigned long sleepTimeoutMs = SETTINGS.getSleepTimeoutMs();
   if (millis() - lastActivityTime >= sleepTimeoutMs) {
-    Serial.printf("[%lu] [SLP] Auto-sleep triggered after %lu ms of inactivity\n", millis(), sleepTimeoutMs);
+    LOG_DBG("SLP", "Auto-sleep triggered after %lu ms of inactivity", sleepTimeoutMs);
     enterDeepSleep();
     // This should never be hit as `enterDeepSleep` calls esp_deep_sleep_start
     return;
@@ -403,8 +420,7 @@ void loop() {
   if (loopDuration > maxLoopDuration) {
     maxLoopDuration = loopDuration;
     if (maxLoopDuration > 50) {
-      Serial.printf("[%lu] [LOOP] New max loop duration: %lu ms (activity: %lu ms)\n", millis(), maxLoopDuration,
-                    activityDuration);
+      LOG_DBG("LOOP", "New max loop duration: %lu ms (activity: %lu ms)", maxLoopDuration, activityDuration);
     }
   }