Client Side Tracking For Tasks

# Problem

We don't currently have mixpanel tracking for understanding task creation and management.

## Subtasks

1. Viewed project tasks tab (properties: project_name, project_id)
2. Clicked create new task button (properties: project_name, project_id)
3. Created new task (properties: project_name, project_id)
4. Viewed project task (properties: project_name, project_id, task_id)
5. Added skill to task (properties: project_name, project_id)
6. Change task status (properties: project_name, project_id, task_id, moved_from_column, moved_to_column)
7. Assigned a user to a task (properties: project_name, project_id, assignee_user_name, task_id)
8. Edited task (if tasks are editable), (properties: project_name, project_id, task_id)

該 issue 未指定任何檔案或測試。首先定位現有的 Mixpanel 追蹤和任務 UI 入口點，然後將列出的每個任務操作對應到其目前的 handler，並驗證所要求的屬性。完成意味著指定的任務互動會發出所要求的分析資料，包括有條件的 task-edit 事件。

由索引模型根據 Issue 內容生成。