fix: Fixed Image Sizing When No Width is Set (#1002)

## Summary

* **What is the goal of this PR?** (e.g., Implements the new feature for
file uploading.)
When no width is set for an image, the image currently automatically
sets to the width of the page. However, with this fix, the parser will
use the height and aspect ratio of the image to properly set a height
for it. See below example:


Before:

![IMG_8862](https://github.com/user-attachments/assets/64b3b92f-1165-45ca-8bdb-8e69613d9725)

After:

![IMG_8863](https://github.com/user-attachments/assets/5cb99b12-d150-4b37-ae4c-c8a20eb9f3a0)


* **What changes are included?✱
Changes to the CSS parser

## Additional Context

* Add any other information that might be helpful for the reviewer
(e.g., performance implications, potential risks,
  specific areas to focus on).

---

### AI Usage

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Did you use AI tools to help write this code? YES, Cursor

lib/Epub/Epub/css/CssStyle.h

@@ -69,6 +69,8 @@ struct CssPropertyFlags {
   uint16_t paddingBottom : 1;
   uint16_t paddingLeft : 1;
   uint16_t paddingRight : 1;
+  uint16_t imageHeight : 1;
+  uint16_t imageWidth : 1;
 
   CssPropertyFlags()
       : textAlign(0),
@@ -83,17 +85,21 @@ struct CssPropertyFlags {
         paddingTop(0),
         paddingBottom(0),
         paddingLeft(0),
-        paddingRight(0) {}
+        paddingRight(0),
+        imageHeight(0),
+        imageWidth(0) {}
 
   [[nodiscard]] bool anySet() const {
     return textAlign || fontStyle || fontWeight || textDecoration || textIndent || marginTop || marginBottom ||
-           marginLeft || marginRight || paddingTop || paddingBottom || paddingLeft || paddingRight;
+           marginLeft || marginRight || paddingTop || paddingBottom || paddingLeft || paddingRight || imageHeight ||
+           imageWidth;
   }
 
   void clearAll() {
     textAlign = fontStyle = fontWeight = textDecoration = textIndent = 0;
     marginTop = marginBottom = marginLeft = marginRight = 0;
     paddingTop = paddingBottom = paddingLeft = paddingRight = 0;
+    imageHeight = imageWidth = 0;
   }
 };
 
@@ -115,6 +121,8 @@ struct CssStyle {
   CssLength paddingBottom;  // Padding after
   CssLength paddingLeft;    // Padding left
   CssLength paddingRight;   // Padding right
+  CssLength imageHeight;    // Height for img (e.g. 2em) – width derived from aspect ratio when only height set
+  CssLength imageWidth;     // Width for img when both or only width set
 
   CssPropertyFlags defined;  // Tracks which properties were explicitly set
 
@@ -173,6 +181,14 @@ struct CssStyle {
       paddingRight = base.paddingRight;
       defined.paddingRight = 1;
     }
+    if (base.hasImageHeight()) {
+      imageHeight = base.imageHeight;
+      defined.imageHeight = 1;
+    }
+    if (base.hasImageWidth()) {
+      imageWidth = base.imageWidth;
+      defined.imageWidth = 1;
+    }
   }
 
   [[nodiscard]] bool hasTextAlign() const { return defined.textAlign; }
@@ -188,6 +204,8 @@ struct CssStyle {
   [[nodiscard]] bool hasPaddingBottom() const { return defined.paddingBottom; }
   [[nodiscard]] bool hasPaddingLeft() const { return defined.paddingLeft; }
   [[nodiscard]] bool hasPaddingRight() const { return defined.paddingRight; }
+  [[nodiscard]] bool hasImageHeight() const { return defined.imageHeight; }
+  [[nodiscard]] bool hasImageWidth() const { return defined.imageWidth; }
 
   void reset() {
     textAlign = CssTextAlign::Left;
@@ -197,6 +215,7 @@ struct CssStyle {
     textIndent = CssLength{};
     marginTop = marginBottom = marginLeft = marginRight = CssLength{};
     paddingTop = paddingBottom = paddingLeft = paddingRight = CssLength{};
+    imageHeight = imageWidth = CssLength{};
     defined.clearAll();
   }
 };