feat: add button to delete checkpoints only

[roomote]

This PR attempts to address Issue #10801. Feedback and guidance are welcome.

Summary

Adds a "Delete Checkpoints Only" button to the task history panel, allowing users to free up disk space by removing checkpoint data while preserving task history and conversation.

Based on testing by @nh2, deleting checkpoints manually does not break the UI - the checkpoint lines simply disappear, which simplifies the implementation since we do not need to update ui_messages.json.

Changes

Backend

• Added deleteTaskCheckpointsWithId message type to WebviewMessage in types package
• Added deleteTaskCheckpointsWithId method in ClineProvider.ts that:
  • Deletes the shadow checkpoint service data via ShadowCheckpointService.deleteTask()
  • Removes only the checkpoints directory (not the entire task)
  • Refreshes the webview state
• Added handler in webviewMessageHandler.ts

Frontend

• Created DeleteCheckpointsButton.tsx component (with history icon, supports Shift+Click to skip confirmation)
• Created DeleteCheckpointsDialog.tsx confirmation dialog
• Updated TaskItemFooter.tsx to include the new button (appears in full variant alongside other action buttons)
• Updated TaskItem.tsx to pass through the onDeleteCheckpoints prop
• Updated HistoryView.tsx to wire up the dialog state management
• Added translations to history.json

Tests

• Added unit tests for DeleteCheckpointsButton
• Added unit tests for DeleteCheckpointsDialog

How to Test

1. Open a task that has checkpoints
2. Go to History view
3. You should see a clock/history icon button next to the export button
4. Click it to see the confirmation dialog
5. Confirm deletion - checkpoints are removed, but task history remains
6. Shift+Click to skip confirmation

Closes #10801

---

Important

Add a feature to delete task checkpoints while preserving history, with UI components and tests.

• Backend:
  • Add deleteTaskCheckpointsWithId to WebviewMessage in vscode-extension-host.ts.
  • Implement deleteTaskCheckpointsWithId in ClineProvider.ts to delete checkpoints and refresh webview.
  • Handle deleteTaskCheckpointsWithId in webviewMessageHandler.ts.
• Frontend:
  • Add DeleteCheckpointsButton.tsx for button UI with Shift+Click support.
  • Add DeleteCheckpointsDialog.tsx for confirmation dialog.
  • Update TaskItemFooter.tsx and TaskItem.tsx to include the new button.
  • Update HistoryView.tsx to manage dialog state.
  • Add translations in history.json.
• Tests:
  • Add unit tests for DeleteCheckpointsButton and DeleteCheckpointsDialog.

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[roomote]

Rooviewer   See task on Roo Cloud

Review completed. The implementation correctly follows existing patterns for adding the delete checkpoints feature. Found one minor test quality issue.

• DeleteCheckpointsDialog.spec.tsx:59 - Test "calls onOpenChange when cancel is clicked" is missing assertion for onOpenChange being called

_{Mention @roomote in a comment to request specific changes to this pull request or fix all unresolved issues.}

[roomote]

This test is named "calls onOpenChange when cancel is clicked" but it doesn't actually assert that onOpenChange is called. Compare with the existing DeleteTaskDialog.spec.tsx which properly includes expect(mockOnOpenChange).toHaveBeenCalledWith(false). The missing assertion should be added to verify the behavior claimed by the test name.

Suggested change

	expect(vscode.postMessage).not.toHaveBeenCalled()
	expect(vscode.postMessage).not.toHaveBeenCalled()
	expect(onOpenChange).toHaveBeenCalledWith(false)

_{Fix it with Roo Code or mention @roomote and request a fix.}