fix(ui): unified unknown-char block rendering and display layout fixes

- GxEPDDisplay::print() renders '\xDB' as filled rect for Lemon font,
  matching OLED Lemon block behavior
- Remove translateUTF8ToBlocks override (base class passthrough sufficient)
- transliterateCodepoint fallback changed '?' → '\xDB' for consistency
- drawTextCentered/Right/LeftAlign now call translateUTF8ToBlocks
- isLemonFont() added to DisplayDriver, SH1106Display, GxEPDDisplay
- isLandscape() guarded by EINK_DISPLAY_MODEL to distinguish OLED vs e-ink
- ind_h trims indicator box height only for Lemon font
- getTextWidth disables wrap before getTextBounds, restores after
- QuickMsgScreen: tighter hist_item padding; 2 messages visible with Lemon
- Hibernate hint fits on one line when width allows, splits otherwise
- BLE PIN page shows toggle hint on landscape e-ink
- Remove unused muted_icon bitmap

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/helpers/ui/GxEPDDisplay.h

@@ -83,7 +83,7 @@ public:
     return (_use_lemon ? 10 : 8) * sc;
   }
   void setLemonFont(bool enabled) override { _use_lemon = enabled; }
-
+  bool isLemonFont() const override { return _use_lemon; }
   bool begin();
 
   bool isOn() override { return _isOn; }