feat(News): refactor news service and add sentiment tracking

FinlyticNews/Adapters/Discovery/ArticleDiscoveryAdapter.cs

@@ -0,0 +1,22 @@
+using FinlyticCore.Dtos.News;
+
+namespace FinlyticNews.Adapters.Discovery;
+
+/// <summary>
+/// Abstract base class representing an adapter capable of extracting article URLs from web content.
+/// </summary>
+public abstract class ArticleDiscoveryAdapter
+{
+    /// <summary>
+    /// Gets the unique adapter keyword name used for matching (e.g. "rss", "html").
+    /// </summary>
+    public abstract string Name { get; }
+
+    /// <summary>
+    /// Extracts a list of absolute article URLs from the retrieved web/feed page content.
+    /// </summary>
+    /// <param name="content">The raw text or XML content loaded from the source.</param>
+    /// <param name="sourceUrl">The original URL of the source page (used to resolve relative links).</param>
+    /// <returns>A list of resolved absolute URLs.</returns>
+    public abstract List<DiscoveredArticle> ExtractUrls(string content, string sourceUrl);
+}