fix(db): use init config files for caddy/webdav bind mounts

[SergioChan]

Summary

• switch the webdav config bind mount to ./init/webdav/config.yml so a missing local ./webdav/config.yml is no longer auto-created as a directory
• switch the caddy bind mount to ./init/caddy/conf/Caddyfile so first-run compose up has a guaranteed file source
• keeps data/config directories unchanged (./webdav/data, ./caddy/caddy_data, ./caddy/caddy_config)

Testing

• git diff --check
• Docker compose runtime validation was not runnable in this environment (docker CLI unavailable in current WSL runtime), so this change is limited to static bind-mount path correction against files that exist in-repo under db/init/.

Related

Fixes #405