feat(ads): enhance AdmobInlineAdWidget with banner ad shape configuration

- Add bannerAdShape parameter to AdmobInlineAdWidget for better banner ad customization
- Implement logic to adjust banner ad height based on the specified shape
- Update documentation to reflect new parameter and its usage

Author: fulleni

lib/ads/widgets/admob_inline_ad_widget.dart

@@ -24,15 +24,20 @@ class AdmobInlineAdWidget extends StatefulWidget {
   const AdmobInlineAdWidget({
     required this.inlineAd,
     this.headlineImageStyle,
+    this.bannerAdShape,
     super.key,
   });
 
   /// The generic inline ad model which contains the provider-specific AdMob ad object.
   final InlineAd inlineAd;
 
   /// The user's preference for feed layout, used to determine the ad's visual size.
+  /// This is only relevant for native ads.
   final HeadlineImageStyle? headlineImageStyle;
 
+  /// The preferred shape for banner ads, used for in-article banners.
+  final BannerAdShape? bannerAdShape;
+
   @override
   State<AdmobInlineAdWidget> createState() => _AdmobInlineAdWidgetState();
 }
@@ -107,11 +112,14 @@ class _AdmobInlineAdWidgetState extends State<AdmobInlineAdWidget> {
         NativeAdTemplateType.medium => 340,
       };
     } else if (widget.inlineAd is BannerAd) {
-      // For banner ads, adjust height based on headlineImageStyle.
-      // If largeThumbnail, assume mediumRectangle (300x250), otherwise standard banner (320x50).
-      adHeight = widget.headlineImageStyle == HeadlineImageStyle.largeThumbnail
-          ? 250 // Height for mediumRectangle
-          : 50;
+      // For banner ads, adjust height based on bannerAdShape if provided.
+      // If bannerAdShape is square, use height for mediumRectangle (250).
+      // Otherwise, use height for standard banner (50).
+      adHeight = switch (widget.bannerAdShape) {
+        BannerAdShape.square => 250,
+        BannerAdShape.rectangle => 50,
+        _ => 50, // Default to standard banner height if shape is null or unknown
+      };
     } else {
       // Fallback height for unknown inline ad types.
       adHeight = 100;