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/Interfaces/IContextEventRepository.cs

@@ -0,0 +1,10 @@
+using TaskTracker.Core.Entities;
+
+namespace TaskTracker.Core.Interfaces;
+
+public interface IContextEventRepository
+{
+    Task<ContextEvent> CreateAsync(ContextEvent contextEvent);
+    Task<List<ContextEvent>> GetRecentAsync(int minutes = 30);
+    Task<List<ContextEvent>> GetByTaskIdAsync(int taskId);
+}