Fix: make lower-casing nil-safe in common.cljc

[Tales-K]

• aloof-sort-by: handle nils and non-strings before lower-casing
• ->kebab-case: guard for strings and use clojure.string/lower-case

Prevents TypeError: "toLowerCase" of null in cljs paths.

Description:

Related issue (if applicable): fixes #

Checklist:

• The code change is tested and works locally.
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if necessary
• There is no commented out code in this PR.
• My changes generate no new warnings (check the console)

[codeGlaze]

This is an interesting patch I hadn't considered - I'm curious about how it cropped up for you. What happened that you caught this?

[Tales-K]

This bug occurs with some orcbrew files, I suspect they have something missing but I cannot find what it is.
It happens when you click on "Features" tab, either viewing or editing, for an Aarakocra character, using MegaPak - WotC Books.orcbrew file.

Before applying the fix, the site crashes and the screen turns black,. After the fix, everything works as expected.

Would you like me to add a warn log to the method or something like that?

[codeGlaze]

I was mostly curious how you found it so I can try to recreate it! :D

I'm always happy to have better error handling :)

[codeGlaze]

Looks good, nice catch!