Hollow out backlight bulb icon when manual light is off

App/bitmaps.c

@@ -57,6 +57,21 @@ const uint8_t gFontLight[9] =
     0b00001100,
 };
 
+// Same bulb outline as gFontLight with the inner filament removed,
+// used when the manual backlight is currently off
+const uint8_t gFontLightOff[9] =
+{
+    0b00001100,
+    0b00010010,
+    0b00100001,
+    0b01100001,
+    0b01100001,
+    0b01100001,
+    0b00100001,
+    0b00010010,
+    0b00001100,
+};
+
 const uint8_t gFontMute[12] =
 {
     0b00011100,

App/bitmaps.h

@@ -12,6 +12,7 @@ extern const uint8_t gFontS[6];
 
 extern const uint8_t gFontKeyLock[9];
 extern const uint8_t gFontLight[9];
+extern const uint8_t gFontLightOff[9];
 extern const uint8_t gFontMute[12];
 
 extern const uint8_t gFontXB[2][6];

App/ui/status.c

@@ -260,7 +260,10 @@ void UI_DisplayStatus()
         }
     #endif
     else if (gBackLight) {
-        src = gFontLight;
+        // Distinguish the manual backlight sub-state: BACKLIGHT_TIME == 0
+        // means the light is currently off (hollow bulb), otherwise it is
+        // forced on (bulb with filament). Both glyphs share the same size.
+        src = (gEeprom.BACKLIGHT_TIME == 0) ? gFontLightOff : gFontLight;
         size = sizeof(gFontLight);
     }
     #ifdef ENABLE_FEAT_F4HWN_CHARGING_C