- `komodo::linalg::Matrix::random` is tested
- `komodo::linalg::Matrix::inverse` is tested on more matrix sizes, from $1$ to $20$ random matrices
- `komodo::field` tests have been double-checked
- pure "recoding" tests from `komodo::fec` have been double-checked
- `end_to_end` and `end_to_end_with_recoding` now runs for $k \in [3, 5]$ and $\rho \in [\frac{1}{2}, \frac{1}{3}]$ with $n = \lfloor \frac{k}{\rho} \rfloor$
- all "_$k$ among $n + t$_" combinations are tested with `try_all_decoding_combinations`, possibly with some removals in case recoding is involved with `is_inside`

>  **Important**  
> on my machine, `make test` goes from less than 8sec on latest `main` to around 40sec with this MR