fix(ci): resolve shellcheck warnings and trivy exit-code for base images

Merge pull request #1 from feliperbroering/security-hardening

Comprehensive security hardening across all layers

fix(docs): replace Unicode box-drawing with ASCII in architecture diagram

fix(ci): suppress SC2034 for unused CYAN color variable in install.sh

fix(ci): suppress SC2034 for future-use variables in setup.sh

fix(ci): replace ls with find in restore.sh (SC2012)

fix(ci): add || exit to cd commands (SC2164)

fix(ci): resolve SC2016 - escape $ for literal dollar in printf

fix(ci): resolve Shell Script Lint and Secret Detection failures

feat: create-openclaw-agent CLI - setup wizard, GCP provider, open source docs

Initial commit: OpenClaw self-hosting template for GCE