mod: improve home screen with adaptive layouts, clock, and set time

- 1-book view: horizontal layout with cover left, title/author right
- 2-3 book view: fix cover stretching by preserving aspect ratio
- 0-book view: show "Choose something to read" placeholder
- Selection highlight now fully contains title and author text
- Add optional clock display in home screen header (AM/PM or 24H)
- Add "Home Screen Clock" setting under Display
- Add "Set Time" activity for manual clock setting via Settings
- Increase homeCoverTileHeight to 310 for title/author breathing room

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

src/CrossPointSettings.cpp

@@ -138,6 +138,7 @@ uint8_t CrossPointSettings::writeSettings(FsFile& file, bool count_only) const {
   // New fields added at end for backward compatibility
   writer.writeItem(file, preferredPortrait);
   writer.writeItem(file, preferredLandscape);
+  writer.writeItem(file, homeScreenClock);
 
   return writer.item_count;
 }
@@ -273,6 +274,8 @@ bool CrossPointSettings::loadFromFile() {
     if (++settingsRead >= fileSettingsCount) break;
     readAndValidate(inputFile, preferredLandscape, ORIENTATION_COUNT);
     if (++settingsRead >= fileSettingsCount) break;
+    readAndValidate(inputFile, homeScreenClock, CLOCK_FORMAT_COUNT);
+    if (++settingsRead >= fileSettingsCount) break;
   } while (false);
 
   if (frontButtonMappingRead) {