fix: prevent checkpoint restore from auto-resuming tasks

[roomote]

This PR attempts to address Issue #10402. Feedback and guidance are welcome.

Problem

When using checkpoint restore, the tasks appear to be restored, but the UI does not update properly. This happens because the restored tasks are re-executed (auto-resumed) instead of just displaying the restored state.

Root Cause

The issue occurs in the checkpoint restore flow:

1. checkpointRestore() calls provider?.cancelTask() after completing the restore
2. cancelTask() calls createTaskWithHistoryItem() with default startTask: true
3. This causes the task to auto-resume and re-execute its message history

Solution

Pass startTask: false through the checkpoint restore flow to prevent auto-resumption:

• Modified ClineProvider.cancelTask() to accept optional { startTask?: boolean } parameter
• Updated checkpointRestore() to pass { startTask: false } to cancelTask()
• Updated handleCheckpointRestoreOperation() delete operation to pass { startTask: false } to createTaskWithHistoryItem()

Test Plan

• Verified all existing checkpoint tests pass
• Verified all checkpointRestoreHandler tests pass
• TypeScript type checking passes

Verification

To verify this fix:

1. Create a task with checkpoint enabled
2. Make some progress and create multiple checkpoints
3. Use checkpoint restore (either "Restore files" or "Restore files & tasks")
4. Confirm the UI displays the restored state without re-executing the tasks

[roomote]

Rooviewer   See task on Roo Cloud

Review complete. No issues found.

The implementation correctly addresses the root cause: checkpoint restore was causing tasks to auto-resume and re-execute message history. The fix adds an optional startTask parameter to cancelTask() that defaults to true for backward compatibility, while passing false in checkpoint restore flows to prevent auto-resumption.

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