safety: resolve all TODOs

```bash
$ rg TODO -c
gm.h:1
chrysler.h:1
ford.h:1
volkswagen_mlb.h:2
subaru.h:1
chrysler_cusw.h:1
tesla.h:1
subaru_preglobal.h:1
hyundai_common.h:1
```

Run `rg TODO -c` to reproduce the listed occurrences, then inspect the TODOs in gm.h, chrysler.h, ford.h, volkswagen_mlb.h, subaru.h, chrysler_cusw.h, tesla.h, subaru_preglobal.h, and hyundai_common.h. Determine the intended resolution for each item from its surrounding context; done means no listed TODOs remain and the relevant checks pass.

Written by the indexing model from the issue text.