fix: Hide button hints in landscape CW mode (#637)

## Summary

* This change hides the button hints from overlapping chapter titles
when in landscape CW mode.

Before

![Before](https://github.com/user-attachments/assets/3015a9b3-3fa5-443b-a641-3e65841a6fbc)
After

![After](https://github.com/user-attachments/assets/011de15d-5ae6-429c-8f91-d8f37abe52d9)

## Additional Context

* I initially considered implementing an offset fix, but with potential
UI changes on the horizon, hiding the button hints appears to be the
simplest solution for now.

---

### AI Usage

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Did you use AI tools to help write this code? < Partially >

src/activities/reader/EpubReaderChapterSelectionActivity.cpp

@@ -206,8 +206,11 @@ void EpubReaderChapterSelectionActivity::renderScreen() {
     }
   }
 
-  const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
-  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+  // Skip button hints in landscape CW mode (they overlap content)
+  if (renderer.getOrientation() != GfxRenderer::LandscapeClockwise) {
+    const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+  }
 
   renderer.displayBuffer();
 }

src/activities/reader/XtcReaderChapterSelectionActivity.cpp

@@ -149,8 +149,11 @@ void XtcReaderChapterSelectionActivity::renderScreen() {
     renderer.drawText(UI_10_FONT_ID, 20, 60 + (i % pageItems) * 30, title, i != selectorIndex);
   }
 
-  const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
-  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+  // Skip button hints in landscape CW mode (they overlap content)
+  if (renderer.getOrientation() != GfxRenderer::LandscapeClockwise) {
+    const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+  }
 
   renderer.displayBuffer();
 }