Prevents shell from expanding '$' in Gitea-rendered secret values.
Without the quote, a password like 'P@$s5w0rd' has '$s5w0rd' silently
expanded to '' — writing a truncated value to obs-secrets.env.
'<<'EOF'' suppresses shell expansion; Gitea's '${{ }}' template
rendering already ran before the shell sees the script.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>