Checkpoints not getting recorded after compaction

### Describe the bug

I had a long running session and ran compaction for probably the fourth time. I wanted to see what the checkpoints looked like, but when I ran the command `/session checkpoints`, it said no checkpoints yet. Where are they then??

### Affected version

1.0.39

### Steps to reproduce the behavior

Have a session with some data in it. Have it run compaction a few times over the course of the conversation.
Run `/session checkpoints` and see the "No checkpoints yet." output

### Expected behavior

I should see a list of checkpoints and some info about what happened in each.

### Additional context

Windows 11 using Windows Terminal

Another image where I tried `/session checkpoints 2`

Reproduce the issue in a long-running session by triggering compaction several times, then run `/session checkpoints` and `/session checkpoints 2` to confirm the empty output. Trace the checkpoint recording and `/session checkpoints` command paths, then verify that recorded checkpoints and their details are listed after compaction.

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