Database migration did not find place after upgrading from python to rust

If I understand https://docs.activitywatch.net/en/latest/migrating.html correctly, when starting aw-server-rust, the old database should automatically be migrated. It apparently didn't happen for me. Some observations:

* Python version was configured without "storage" set in the toml-file, default peevee assumed
* The web interface does show that new events come into the database, but it does not show any old events
* The database file `$HOME/.local/share/activitywatch/aw-server-rust/sqlite.db` is 60MB big, that clearly indicates it still has old data.
* Here are the logs:

```
$ journalctl --user -u aw-server
Dec 08 09:25:20 archlinux systemd[1099]: Starting ActivityWatch Server (Rust implementation)...
Dec 08 09:25:20 archlinux aw-server[3765361]: [2025-12-08 09:25:20][INFO][aw_server]: Using DB at path "/home/tobias/.local/share/activitywatch/aw-server-rust/sqlite.db"
Dec 08 09:25:20 archlinux aw-server[3765361]: [2025-12-08 09:25:20][INFO][aw_server]: Using aw-webui assets at path None
Dec 08 09:25:20 archlinux aw-server[3765361]: [2025-12-08 09:25:20][INFO][aw_server::endpoints]: Starting aw-server-rust at 127.0.0.1:5600
Dec 08 09:25:20 archlinux aw-server[3765361]: [2025-12-08 09:25:20][WARN][rocket::launch]: Rocket has launched from http://127.0.0.1:5600
Dec 08 09:25:20 archlinux systemd[1099]: Started ActivityWatch Server (Rust implementation).
Dec 08 09:26:00 archlinux aw-server[3765361]: [2025-12-08 09:26:00][WARN][rocket::response::responder::_]: Response was `None`.
Dec 08 09:26:00 archlinux aw-server[3765361]: [2025-12-08 09:26:00][WARN][rocket::server::_]: No 404 catcher registered. Using Rocket default.
```