fix: Re-apply upstream PRs #1005, #1010, #1003

Re-applies changes that were accidentally discarded during a prior
dry-run cherry-pick reset (git checkout -- .).

- PR #1005: Use HalPowerManager for battery percentage (uint16_t return
  type, remove Battery.h, update theme files)
- PR #1010: Fix dangling pointer in onGoToReader()
- PR #1003: Render image placeholders while waiting for decode (adds
  isCached, renderPlaceholder, renderTextOnly, countUncachedImages,
  renderImagePlaceholders)

Co-authored-by: Cursor <cursoragent@cursor.com>

src/Battery.h

@@ -1,6 +0,0 @@
-#pragma once
-#include <BatteryMonitor.h>
-
-#define BAT_GPIO0 0  // Battery voltage
-
-static BatteryMonitor battery(BAT_GPIO0);

src/activities/home/HomeActivity.cpp

@@ -13,7 +13,6 @@
 #include <cstring>
 #include <vector>
 
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"

src/activities/reader/EpubReaderActivity.cpp

@@ -1020,6 +1020,14 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
   // Force special handling for pages with images when anti-aliasing is on
   bool imagePageWithAA = page->hasImages() && SETTINGS.textAntiAliasing;
 
+  if (page->countUncachedImages() > 0) {
+    page->renderTextOnly(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
+    page->renderImagePlaceholders(renderer, orientedMarginLeft, orientedMarginTop);
+    renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
+    renderer.displayBuffer();
+    renderer.clearScreen();
+  }
+
   page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
 
   // Draw bookmark ribbon indicator in top-right corner if current page is bookmarked

src/components/themes/BaseTheme.cpp

@@ -1,6 +1,7 @@
 #include "BaseTheme.h"
 
 #include <GfxRenderer.h>
+#include <HalPowerManager.h>
 #include <HalStorage.h>
 #include <Logging.h>
 #include <Utf8.h>
@@ -9,7 +10,6 @@
 #include <ctime>
 #include <string>
 
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "I18n.h"
 #include "RecentBooksStore.h"
@@ -49,7 +49,7 @@ void drawBatteryIcon(const GfxRenderer& renderer, int x, int y, int battWidth, i
 
 void BaseTheme::drawBatteryLeft(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Left aligned: icon on left, percentage on right (reader mode)
-  const uint16_t percentage = battery.readPercentage();
+  const uint16_t percentage = powerManager.getBatteryPercentage();
   const int y = rect.y + 6;
 
   if (showPercentage) {
@@ -64,7 +64,7 @@ void BaseTheme::drawBatteryLeft(const GfxRenderer& renderer, Rect rect, const bo
 void BaseTheme::drawBatteryRight(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Right aligned: percentage on left, icon on right (UI headers)
   // rect.x is already positioned for the icon (drawHeader calculated it)
-  const uint16_t percentage = battery.readPercentage();
+  const uint16_t percentage = powerManager.getBatteryPercentage();
   const int y = rect.y + 6;
 
   if (showPercentage) {

src/components/themes/lyra/LyraTheme.cpp

@@ -1,6 +1,7 @@
 #include "LyraTheme.h"
 
 #include <GfxRenderer.h>
+#include <HalPowerManager.h>
 #include <HalStorage.h>
 #include <I18n.h>
 #include <Utf8.h>
@@ -10,7 +11,6 @@
 #include <string>
 #include <vector>
 
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "RecentBooksStore.h"
 #include "components/UITheme.h"
@@ -88,7 +88,7 @@ const uint8_t* iconForName(UIIcon icon, int size) {
 
 void LyraTheme::drawBatteryLeft(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Left aligned: icon on left, percentage on right (reader mode)
-  const uint16_t percentage = battery.readPercentage();
+  const uint16_t percentage = powerManager.getBatteryPercentage();
   const int y = rect.y + 6;
   const int battWidth = LyraMetrics::values.batteryWidth;
 
@@ -125,7 +125,7 @@ void LyraTheme::drawBatteryLeft(const GfxRenderer& renderer, Rect rect, const bo
 
 void LyraTheme::drawBatteryRight(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Right aligned: percentage on left, icon on right (UI headers)
-  const uint16_t percentage = battery.readPercentage();
+  const uint16_t percentage = powerManager.getBatteryPercentage();
   const int y = rect.y + 6;
   const int battWidth = LyraMetrics::values.batteryWidth;
 

src/main.cpp

@@ -15,7 +15,6 @@
 #include <cstring>
 #include <ctime>
 
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "KOReaderCredentialStore.h"
@@ -227,9 +226,9 @@ void onGoHome();
 void onGoToMyLibraryWithPath(const std::string& path);
 void onGoToRecentBooks();
 void onGoToReader(const std::string& initialEpubPath) {
+  const std::string bookPath = initialEpubPath;  // Copy before exitActivity() invalidates the reference
   exitActivity();
-  enterNewActivity(
-      new ReaderActivity(renderer, mappedInputManager, initialEpubPath, onGoHome, onGoToMyLibraryWithPath));
+  enterNewActivity(new ReaderActivity(renderer, mappedInputManager, bookPath, onGoHome, onGoToMyLibraryWithPath));
 }
 
 void onGoToFileTransfer() {