Fix chown and permission issues

[feederbox826]

size comparison

alpine: 791.47 -> 434.53 (-356.94MB)
hwaccel: 1380 -> 1120 (-260MB)

entrypoint.sh

🔑 chown and permissions management

• remove SKIP_CHOWN
• only set u=rwx and owner when chown-ing
• split into reown/reown_r for non-recursive chown

🧩 stashapp/stash compatibility mode

• add consistent STASHAPP_STASH_CONFIG
• more robust checks for permissions
• don't fake ROOTLESS

🚚/🚛 Migration

• move config backups as well

🐍 Python

• be picky when finding python reqs
• drop bencoder.pyx for fastbencode
• drop build dependencies for python

📋 Startup checks

• add check for common directories
• be more verbose with error logs

🎭 user changing

• default to 911:911 in docker image as well
• log explanation if root is preserved

other

• remove unnecessary curly brackets

Documentation

• add develop tag
• fix typo for NVENV -> NVENC
• reformat readme
• update branding

🐳 docker misc changes

• remove unused UV_VERSION
• fix arm64 installing intel drivers