feat: add runtime display rotation setting for e-ink builds

Adds Settings > Display > Rotation (0°/90°/180°/270°) that persists to
NodePrefs and is applied on startup. Falls back to compile-time
DISPLAY_ROTATION when the field is missing from an older prefs file.

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

examples/companion_radio/ui-new/SettingsScreen.h

@@ -15,6 +15,9 @@ class SettingsScreen : public UIScreen {
     CLOCK_SECONDS,
     CLOCK_FORMAT,
     FONT,
+#if defined(EINK_DISPLAY_MODEL)
+    ROTATION,
+#endif
     // Sound section
     SECTION_SOUND,
     BUZZER,
@@ -321,6 +324,14 @@ class SettingsScreen : public UIScreen {
       display.print("Font");
       display.setCursor(VAL_X, y);
       display.print((p && p->use_lemon_font) ? "Lemon" : "Default");
+#if defined(EINK_DISPLAY_MODEL)
+    } else if (item == ROTATION) {
+      display.print("Rotation");
+      display.setCursor(VAL_X, y);
+      { static const char* ROT_LABELS[] = { "0deg", "90deg", "180deg", "270deg" };
+        uint8_t r = p ? (p->display_rotation & 3) : 0;
+        display.print(ROT_LABELS[r]); }
+#endif
     } else if (item == DM_FILTER) {
       display.print("DM");
       display.setCursor(VAL_X, y);
@@ -517,6 +528,14 @@ public:
       _dirty = true;
       return true;
     }
+#if defined(EINK_DISPLAY_MODEL)
+    if (_selected == ROTATION && p && (left || right || enter)) {
+      p->display_rotation = (p->display_rotation + (left ? 3 : 1)) & 3;
+      _task->applyRotation();
+      _dirty = true;
+      return true;
+    }
+#endif
     if (_selected == DM_FILTER && p && (left || right || enter)) {
       p->dm_show_all = p->dm_show_all ? 0 : 1;
       _dirty = true;

examples/companion_radio/ui-new/UITask.cpp

@@ -817,6 +817,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
 
   applyBrightness();
   applyFont();
+  applyRotation();
 }
 
 void UITask::gotoSettingsScreen() {
@@ -1565,6 +1566,13 @@ void UITask::applyFont() {
   }
 }
 
+void UITask::applyRotation() {
+  if (_display != NULL && _node_prefs != NULL) {
+    _display->setDisplayRotation(_node_prefs->display_rotation);
+    _next_refresh = 0;
+  }
+}
+
 void UITask::setBrightnessLevel(uint8_t level) {
   if (_node_prefs == NULL) return;
   if (level > 4) level = 4;

examples/companion_radio/ui-new/UITask.h

@@ -159,6 +159,7 @@ public:
   void applyTxPower();
   void applyGPSInterval();
   void applyFont();
+  void applyRotation();
   uint32_t autoOffMillis() const {
     if (!_node_prefs || _node_prefs->auto_off_secs == 0) return 0;
     return (uint32_t)_node_prefs->auto_off_secs * 1000UL;