refactor(ads): improve inline ad caching and resource management

- Add `removeAd` method to temporarily remove ads from cache without disposal
- Update `setAd` to use AdService for disposing old ads' resources
- Refactor `clearCache` to directly dispose ads instead of using `removeAndDisposeAd`
- Update method comments for clarity and accuracy

Author: fulleni

lib/ads/inline_ad_cache_service.dart

@@ -72,7 +72,7 @@ class InlineAdCacheService {
   /// If [ad] is `null`, it effectively removes the entry for [id].
   void setAd(String id, InlineAd? ad) {
     if (_cache.containsKey(id) && _cache[id] != null) {
-      // If an old ad exists for this ID, dispose of its resources.
+      // If an old ad exists for this ID, dispose of its resources via AdService.
       _logger.info(
         'Disposing old inline ad for ID "$id" before caching new one.',
       );
@@ -88,6 +88,19 @@ class InlineAdCacheService {
     }
   }
 
+  /// Removes an [InlineAd] from the cache without disposing its resources.
+  ///
+  /// This method should be used when an ad is temporarily removed from the UI
+  /// (e.g., scrolled off-screen) but its resources might still be needed later.
+  void removeAd(String id) {
+    if (_cache.containsKey(id)) {
+      _cache.remove(id);
+      _logger.info('Removed inline ad with ID "$id" from cache (no disposal).');
+    } else {
+      _logger.info('Inline ad with ID "$id" not found in cache for removal.');
+    }
+  }
+
   /// Removes an [InlineAd] from the cache and disposes its resources.
   ///
   /// This method should be used when an ad is permanently removed from the UI
@@ -96,7 +109,7 @@ class InlineAdCacheService {
     final ad = _cache[id];
     if (ad != null) {
       _logger.info('Removing and disposing inline ad with ID "$id".');
-      _adService.disposeAd(ad);
+      _adService.disposeAd(ad); // Delegate disposal to AdService
       _cache.remove(id);
     } else {
       _logger.info('Inline ad with ID "$id" not found in cache for disposal.');
@@ -112,9 +125,8 @@ class InlineAdCacheService {
     _logger.info(
       'Clearing all cached inline ads and disposing their resources.',
     );
-    for (final id in _cache.keys.toList()) {
-      // Use the new removeAndDisposeAd method for consistent disposal.
-      removeAndDisposeAd(id);
+    for (final ad in _cache.values.whereType<InlineAd>()) {
+      _adService.disposeAd(ad); // Delegate disposal to AdService
     }
     _cache.clear(); // Ensure cache is empty after disposal attempts.
     _logger.info('All cached inline ads cleared.');