[FEATURE] Remove unused code

[the-voidl]

Description

During the work on #340 I recognized some things I did not directly work into a PR:

• SECRET_MASTER_KEY config value is not used anymore?
• What is noise.png for? It is used in https://github.com/HemmeligOrg/Hemmelig.app/blob/main/client/routes/home/index.jsx#L587 but there is no route
• A lot (or most? all?) of the code in tailwind.config.js is not used, while client/index.css seems to be the source of truth. This would need a bigger rework from my current point of view

Screenshots

No response

Additional information

No response

[bjarneo]

I need to look into this as I do not remember. Thanks for looking into improvements for this codebase!"

[bjarneo]

local folder ./data/hemmelig stays empty? Was it replaced by /var/tmp/hemmelig/upload/files/?

Where exactly did you mean here?

[the-voidl]

local folder ./data/hemmelig stays empty? Was it replaced by /var/tmp/hemmelig/upload/files/?

Where exactly did you mean here?

Just checked again and it seems that I confused something there. This folder is still used when uploading a file 👍

[bjarneo]

#447