[BUG] Pending tasks cannot be removed — X button has no effect

Description

The task panel displays multiple pending tasks that have been marked as completed. Clicking the X button next to each task has no effect — the tasks remain in the pending state and cannot be removed from the UI.

Environment

• Claude Code CLI
• No message compaction occurred

Steps to Reproduce

1. Create a task list with TodoWrite containing multiple items
2. Mark tasks as completed (status: completed)
3. Attempt to close/remove tasks by clicking the X button in the UI
4. Observe: X button click has no visible effect

Pending Tasks Visible (stuck in UI)

• [REDACTED: Infrastructure setup task]
• [REDACTED: Code generation task]
• [REDACTED: Native patching task]
• [REDACTED: Executor build task]
• [REDACTED: Local executor build task]
• [REDACTED: Phase completion task]
• [REDACTED: Client execution task]
• [REDACTED: Configuration reading task]
• [REDACTED: File installation tasks (×2)]
• [REDACTED: Test execution task]
• [REDACTED: Phase detail task]
• [REDACTED: Bug fix tasks (×2)]
• [REDACTED: Import-related tasks (×2)]

Expected Behavior

Completed tasks should be removable from the UI via the X button

Actual Behavior

X button click has no effect; tasks remain visible and stuck in the pending state

Additional Context

• Approximately 15+ tasks affected
• No error messages in console
• Tasks remain even after session reload attempts