feat: quick rotate option in epub reader menu (#685)

## Summary

* adds rotation setting in epub reader menu, actual rotation happens on
going back
* improves button hint drawing to draw correctly in all orientations

<img width="860" height="1147" alt="image"
src="https://github.com/user-attachments/assets/91ceeca6-729f-4304-b68a-e412f6e2c9a7"
/>


---

### AI Usage

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please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? _**< PARTIALLY  >**_

src/activities/reader/EpubReaderActivity.cpp

@@ -20,22 +20,10 @@ constexpr unsigned long goHomeMs = 1000;
 constexpr int statusBarMargin = 19;
 constexpr int progressBarMarginTop = 1;
 
-}  // namespace
-
-void EpubReaderActivity::taskTrampoline(void* param) {
-  auto* self = static_cast<EpubReaderActivity*>(param);
-  self->displayTaskLoop();
-}
-
-void EpubReaderActivity::onEnter() {
-  ActivityWithSubactivity::onEnter();
-
-  if (!epub) {
-    return;
-  }
-
-  // Configure screen orientation based on settings
-  switch (SETTINGS.orientation) {
+// Apply the logical reader orientation to the renderer.
+// This centralizes orientation mapping so we don't duplicate switch logic elsewhere.
+void applyReaderOrientation(GfxRenderer& renderer, const uint8_t orientation) {
+  switch (orientation) {
     case CrossPointSettings::ORIENTATION::PORTRAIT:
       renderer.setOrientation(GfxRenderer::Orientation::Portrait);
       break;
@@ -51,6 +39,25 @@ void EpubReaderActivity::onEnter() {
     default:
       break;
   }
+}
+
+}  // namespace
+
+void EpubReaderActivity::taskTrampoline(void* param) {
+  auto* self = static_cast<EpubReaderActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void EpubReaderActivity::onEnter() {
+  ActivityWithSubactivity::onEnter();
+
+  if (!epub) {
+    return;
+  }
+
+  // Configure screen orientation based on settings
+  // NOTE: This affects layout math and must be applied before any render calls.
+  applyReaderOrientation(renderer, SETTINGS.orientation);
 
   renderingMutex = xSemaphoreCreateMutex();
 
@@ -129,11 +136,10 @@ void EpubReaderActivity::loop() {
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
     // Don't start activity transition while rendering
     xSemaphoreTake(renderingMutex, portMAX_DELAY);
-    const int currentPage = section ? section->currentPage : 0;
-    const int totalPages = section ? section->pageCount : 0;
     exitActivity();
     enterNewActivity(new EpubReaderMenuActivity(
-        this->renderer, this->mappedInput, epub->getTitle(), [this]() { onReaderMenuBack(); },
+        this->renderer, this->mappedInput, epub->getTitle(), SETTINGS.orientation,
+        [this](const uint8_t orientation) { onReaderMenuBack(orientation); },
         [this](EpubReaderMenuActivity::MenuAction action) { onReaderMenuConfirm(action); }));
     xSemaphoreGive(renderingMutex);
   }
@@ -222,8 +228,11 @@ void EpubReaderActivity::loop() {
   }
 }
 
-void EpubReaderActivity::onReaderMenuBack() {
+void EpubReaderActivity::onReaderMenuBack(const uint8_t orientation) {
   exitActivity();
+  // Apply the user-selected orientation when the menu is dismissed.
+  // This ensures the menu can be navigated without immediately rotating the screen.
+  applyOrientation(orientation);
   updateRequired = true;
 }
 
@@ -305,6 +314,32 @@ void EpubReaderActivity::onReaderMenuConfirm(EpubReaderMenuActivity::MenuAction
   }
 }
 
+void EpubReaderActivity::applyOrientation(const uint8_t orientation) {
+  // No-op if the selected orientation matches current settings.
+  if (SETTINGS.orientation == orientation) {
+    return;
+  }
+
+  // Preserve current reading position so we can restore after reflow.
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (section) {
+    cachedSpineIndex = currentSpineIndex;
+    cachedChapterTotalPageCount = section->pageCount;
+    nextPageNumber = section->currentPage;
+  }
+
+  // Persist the selection so the reader keeps the new orientation on next launch.
+  SETTINGS.orientation = orientation;
+  SETTINGS.saveToFile();
+
+  // Update renderer orientation to match the new logical coordinate system.
+  applyReaderOrientation(renderer, SETTINGS.orientation);
+
+  // Reset section to force re-layout in the new orientation.
+  section.reset();
+  xSemaphoreGive(renderingMutex);
+}
+
 void EpubReaderActivity::displayTaskLoop() {
   while (true) {
     if (updateRequired) {