feat: add CSV feed and GBM examples

- Add CsvFeedExample console app demonstrating CSV data loading and streaming
- Add GbmExample console app for geometric Brownian motion feed
- Add CoreTypes example project
- Include daily_IBM.csv test data file
- Configure project files for .NET 10.0 with quantalib dependency

examples/feeds/CsvFeedExample.cs

@@ -0,0 +1,47 @@
+using QuanTAlib;
+
+// Example: Loading and streaming IBM daily data from CSV
+var csvPath = "daily_IBM.csv";
+
+// Create feed from CSV file
+var feed = new CsvFeed(csvPath);
+
+Console.WriteLine("=== CSV Feed Example: IBM Daily Data ===\n");
+
+// Example 1: Stream through first 5 bars
+Console.WriteLine("1. Streaming first 5 bars:");
+for (int i = 0; i < 5; i++)
+{
+    var bar = feed.Next(isNew: true);
+    Console.WriteLine($"   {bar.AsDateTime:yyyy-MM-dd}: O={bar.Open:F2}, H={bar.High:F2}, L={bar.Low:F2}, C={bar.Close:F2}, V={bar.Volume:F0}");
+}
+
+// Example 2: Fetch a specific date range
+Console.WriteLine("\n2. Fetching 10 bars starting from July 2025:");
+var startTime = new DateTime(2025, 7, 1, 0, 0, 0, DateTimeKind.Utc).Ticks;
+var series = feed.Fetch(10, startTime, TimeSpan.FromDays(1));
+Console.WriteLine($"   Retrieved {series.Count} bars");
+foreach (var bar in series)
+{
+    Console.WriteLine($"   {bar.AsDateTime:yyyy-MM-dd}: Close={bar.Close:F2}");
+}
+
+// Example 3: Demonstrate isNew parameter
+Console.WriteLine("\n3. Demonstrating isNew parameter (new bar vs update):");
+var bar1 = feed.Next(isNew: true);
+Console.WriteLine($"   New bar: {bar1.AsDateTime:yyyy-MM-dd} Close={bar1.Close:F2}");
+
+var bar1Update = feed.Next(isNew: false);
+Console.WriteLine($"   Update (same bar): {bar1Update.AsDateTime:yyyy-MM-dd} Close={bar1Update.Close:F2}");
+
+var bar2 = feed.Next(isNew: true);
+Console.WriteLine($"   Next bar: {bar2.AsDateTime:yyyy-MM-dd} Close={bar2.Close:F2}");
+
+// Example 4: Working with TBarSeries views
+Console.WriteLine("\n4. Accessing OHLCV components via TSeries:");
+var batch = feed.Fetch(5, startTime, TimeSpan.FromDays(1));
+Console.WriteLine($"   Close prices: [{string.Join(", ", batch.Close.Take(5).Select(c => c.Value.ToString("F2")))}]");
+Console.WriteLine($"   High prices: [{string.Join(", ", batch.High.Take(5).Select(h => h.Value.ToString("F2")))}]");
+Console.WriteLine($"   Volumes: [{string.Join(", ", batch.Volume.Take(5).Select(v => v.Value.ToString("F0")))}]");
+
+Console.WriteLine("\n=== Example Complete ===");