chore: initial commit of TaskTracker project

Existing ASP.NET API with vanilla JS SPA, WindowWatcher, Chrome extension, and MCP server.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

TaskTracker.Core/Entities/AppMapping.cs

@@ -0,0 +1,10 @@
+namespace TaskTracker.Core.Entities;
+
+public class AppMapping
+{
+    public int Id { get; set; }
+    public string Pattern { get; set; } = string.Empty;
+    public string MatchType { get; set; } = string.Empty;   // ProcessName, UrlContains, TitleContains
+    public string Category { get; set; } = string.Empty;
+    public string? FriendlyName { get; set; }
+}