fix(cppcheck): resolve style and performance issues

- Remove unused HomeActivity::restoreCoverBuffer
- Use initialization lists in constructors
- Mark single-argument constructors as explicit

lib/ThemeEngine/include/BasicElements.h

@@ -23,7 +23,7 @@ class Container : public UIElement {
   int borderRadius = 0;   // Corner radius (for future rounded rect support)
 
  public:
-  Container(const std::string& id) : UIElement(id) { bgColorExpr = Expression::parse("0xFF"); }
+  explicit Container(const std::string& id) : UIElement(id), bgColorExpr(Expression::parse("0xFF")) {}
   virtual ~Container() {
     for (auto child : children) delete child;
   }
@@ -145,7 +145,7 @@ class Rectangle : public UIElement {
   Expression colorExpr;
 
  public:
-  Rectangle(const std::string& id) : UIElement(id) { colorExpr = Expression::parse("0x00"); }
+  explicit Rectangle(const std::string& id) : UIElement(id), colorExpr(Expression::parse("0x00")) {}
   ElementType getType() const override { return ElementType::Rectangle; }
 
   void setFill(bool f) {
@@ -199,7 +199,7 @@ class Label : public UIElement {
   bool ellipsis = true;  // Truncate with ... if too long
 
  public:
-  Label(const std::string& id) : UIElement(id) { colorExpr = Expression::parse("0x00"); }
+  explicit Label(const std::string& id) : UIElement(id), colorExpr(Expression::parse("0x00")) {}
   ElementType getType() const override { return ElementType::Label; }
 
   void setText(const std::string& expr) {
@@ -367,7 +367,7 @@ class BitmapElement : public UIElement {
   int borderRadius = 0;
 
  public:
-  BitmapElement(const std::string& id) : UIElement(id) {
+  explicit BitmapElement(const std::string& id) : UIElement(id) {
     cacheable = true;  // Bitmaps benefit from caching
   }
   ElementType getType() const override { return ElementType::Bitmap; }
@@ -407,12 +407,13 @@ class ProgressBar : public UIElement {
   int borderWidth = 1;
 
  public:
-  ProgressBar(const std::string& id) : UIElement(id) {
-    valueExpr = Expression::parse("0");
-    maxExpr = Expression::parse("100");
-    fgColorExpr = Expression::parse("0x00");  // Black fill
-    bgColorExpr = Expression::parse("0xFF");  // White background
-  }
+  explicit ProgressBar(const std::string& id)
+      : UIElement(id),
+        valueExpr(Expression::parse("0")),
+        maxExpr(Expression::parse("100")),
+        fgColorExpr(Expression::parse("0x00")),  // Black fill
+        bgColorExpr(Expression::parse("0xFF"))   // White background
+  {}
 
   ElementType getType() const override { return ElementType::ProgressBar; }
 
@@ -480,7 +481,7 @@ class Divider : public UIElement {
   int thickness = 1;
 
  public:
-  Divider(const std::string& id) : UIElement(id) { colorExpr = Expression::parse("0x00"); }
+  explicit Divider(const std::string& id) : UIElement(id), colorExpr(Expression::parse("0x00")) {}
 
   ElementType getType() const override { return ElementType::Divider; }
 
@@ -524,9 +525,9 @@ class BatteryIcon : public UIElement {
   Expression colorExpr;
 
  public:
-  BatteryIcon(const std::string& id) : UIElement(id) {
-    valueExpr = Expression::parse("0");
-    colorExpr = Expression::parse("0x00");  // Black by default
+  explicit BatteryIcon(const std::string& id)
+      : UIElement(id), valueExpr(Expression::parse("0")), colorExpr(Expression::parse("0x00")) {
+    // Black by default
   }
 
   ElementType getType() const override { return ElementType::BatteryIcon; }

lib/ThemeEngine/include/ThemeContext.h

@@ -83,7 +83,7 @@ class ThemeContext {
   }
 
  public:
-  ThemeContext(const ThemeContext* parent = nullptr) : parent(parent) {}
+  explicit ThemeContext(const ThemeContext* parent = nullptr) : parent(parent) {}
 
   void setString(const std::string& key, const std::string& value) { strings[key] = value; }
   void setInt(const std::string& key, int value) { ints[key] = value; }

lib/ThemeEngine/include/ThemeTypes.h

@@ -34,7 +34,7 @@ struct Dimension {
 struct Color {
   uint8_t value;  // For E-Ink: 0 (Black) to 255 (White), or simplified palette
 
-  Color(uint8_t v) : value(v) {}
+  explicit Color(uint8_t v) : value(v) {}
   Color() : value(0) {}
 
   static Color parse(const std::string& str) {

lib/ThemeEngine/include/UIElement.h

@@ -45,7 +45,7 @@ class UIElement {
   }
 
  public:
-  UIElement(const std::string& id) : id(id) { visibleExpr = Expression::parse("true"); }
+  UIElement(const std::string& id) : id(id), visibleExpr(Expression::parse("true")) {}
 
   virtual ~UIElement() {
     if (cachedRender) {

src/activities/home/HomeActivity.cpp

@@ -232,20 +232,7 @@ bool HomeActivity::storeCoverBuffer() {
   return true;
 }
 
-bool HomeActivity::restoreCoverBuffer() {
-  if (!coverBuffer) {
-    return false;
-  }
 
-  uint8_t* frameBuffer = renderer.getFrameBuffer();
-  if (!frameBuffer) {
-    return false;
-  }
-
-  const size_t bufferSize = GfxRenderer::getBufferSize();
-  memcpy(frameBuffer, coverBuffer, bufferSize);
-  return true;
-}
 
 void HomeActivity::freeCoverBuffer() {
   if (coverBuffer) {

src/activities/home/HomeActivity.h

@@ -47,7 +47,7 @@ class HomeActivity final : public Activity {
   void render();
   int getMenuItemCount() const;
   bool storeCoverBuffer();     // Store frame buffer for cover image
-  bool restoreCoverBuffer();   // Restore frame buffer from stored cover
+
   void freeCoverBuffer();      // Free the stored cover buffer
   void loadRecentBooksData();  // Load and cache recent books data