refactor(jikan): add getWithCache helper and reduce duplication

internal/jikan/episodes.go

@@ -12,24 +12,9 @@ func (c *Client) GetEpisodes(ctx context.Context, animeID int, page int) (Episod
 	}
 
 	cacheKey := fmt.Sprintf("anime:%d:episodes:%d", animeID, page)
-	var cached EpisodesResponse
-	if c.getCache(ctx, cacheKey, &cached) {
-		return cached, nil
-	}
-
-	var stale EpisodesResponse
-	hasStale := c.getStaleCache(ctx, cacheKey, &stale)
-
 	var result EpisodesResponse
 	reqURL := fmt.Sprintf("%s/anime/%d/episodes?page=%d", c.baseURL, animeID, page)
-	if err := c.fetchWithRetry(ctx, reqURL, &result); err != nil {
-		if hasStale {
-			return stale, nil
-		}
 
-		return EpisodesResponse{}, err
-	}
-
-	c.setCache(ctx, cacheKey, result, 12*time.Hour)
-	return result, nil
-}
+	err := c.getWithCache(ctx, cacheKey, 12*time.Hour, reqURL, &result)
+	return result, err
+}