* More robust application of access permissions
We were in particular missing directory traversal `+X` in our current recommendations.
Extracted to own shell script so it can easily be invoked.
Update access permissions in Docker to account to be more robust.
#fix https://github.com/FreshRSS/FreshRSS/discussions/5037
* Minor simplification
* Restrict mkdir permissions
Default mkdir permissions are 0777, which is not good for security, so downgrade to 0770.
