Add Tasks panel list view UI

[EhabY]

Summary

Build the task list UI layer with React components, including task creation, task history display, and real-time updates.

Goals

• Collapsible sections for "Create Task" and "Task History"
• Task list with status indicators and action menu (pause, resume, delete)
• Polling for task updates with efficient diffing
• State persistence across webview visibility changes
• Appropriate empty states (error, not supported, no templates)

Resources

• Figma designs
• Notion spec