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/activities/home/HomeActivity.cpp

@@ -9,7 +9,9 @@
 #include <PlaceholderCoverGenerator.h>
 #include <Xtc.h>
 
+#include <cstdio>
 #include <cstring>
+#include <ctime>
 #include <vector>
 
 #include "Battery.h"
@@ -238,6 +240,23 @@ void HomeActivity::render(Activity::RenderLock&&) {
 
   GUI.drawHeader(renderer, Rect{0, metrics.topPadding, pageWidth, metrics.homeTopPadding}, nullptr);
 
+  // Draw clock in the header area (left side) if enabled
+  if (SETTINGS.homeScreenClock != CrossPointSettings::CLOCK_OFF) {
+    time_t now = time(nullptr);
+    struct tm* t = localtime(&now);
+    if (t != nullptr && t->tm_year > 100) {
+      char timeBuf[16];
+      if (SETTINGS.homeScreenClock == CrossPointSettings::CLOCK_24H) {
+        snprintf(timeBuf, sizeof(timeBuf), "%02d:%02d", t->tm_hour, t->tm_min);
+      } else {
+        int hour12 = t->tm_hour % 12;
+        if (hour12 == 0) hour12 = 12;
+        snprintf(timeBuf, sizeof(timeBuf), "%d:%02d %s", hour12, t->tm_min, t->tm_hour >= 12 ? "PM" : "AM");
+      }
+      renderer.drawText(SMALL_FONT_ID, metrics.contentSidePadding, metrics.topPadding, timeBuf, true);
+    }
+  }
+
   GUI.drawRecentBookCover(renderer, Rect{0, metrics.homeTopPadding, pageWidth, metrics.homeCoverTileHeight},
                           recentBooks, selectorIndex, coverRendered, coverBufferStored, bufferRestored,
                           std::bind(&HomeActivity::storeCoverBuffer, this));