Hi, I tried to add a frequency table containing three columns for form, freq_id, value. This had an unexpected effect: the foreign keys for cells and lexemes of the forms table disappeared from the package metadata, which led to validation errors. Instead, the frequency resource gets columns for lexemes and cells, even if they don't appear in the table, and the associated foreign keys. I investigated quickly: the foreignKeys of the forms table are correctly built, but they disappear [here](https://gitlab.com/sbeniamine/paralex/-/blob/main/paralex/meta.py?ref_type=heads#L237) after the `p.infer()` command. No clue why... <details> <summary>How to reproduce</summary> A minimal frequency file as the one attached seems enough to reproduce this behaviour in the latest version of Paralex. [parafin_frequency.csv](/uploads/4f6d977cbf27a16312b7ddc5566af082/parafin_frequency.csv) Add these two lines to the .yml: ``` frequency: path: "parafin_frequency.csv" ``` And run paralex meta. </details>