This commit fixes several issues in the toolbox-base Dockerfile that were identified during the audit:
- Added SHELL directive with pipefail option where pipes are used
- Fixed syntax error in user creation logic by changing 'else if' to 'elif'
- Removed problematic 'cd' usage, replacing with 'git -C' for directory-specific operations
- Added SHELL directive to second stage where pipes are used
- Improved multi-line RUN command formatting with proper semicolon usage
These changes resolve the following Hadolint errors:
- DL4006: Missing pipefail in RUN commands with pipes
- SC1075: Incorrect use of 'else if' instead of 'elif'
- DL3003: Usage of 'cd' instead of WORKDIR
The Dockerfile now passes Hadolint validation when ignoring version pinning
and multiple RUN command warnings, which are expected in this context.