Fix ShellCheck and shfmt violations across repository shell scripts

[WilliamBerryiii]

Summary

After replacing MegaLinter with per-tool GitHub Actions lint workflows (#235, PR #240), the Shell Lint job revealed pre-existing ShellCheck and shfmt violations in repository shell scripts. These violations are currently soft-failed in PR validation.

Details

The shell-lint.yml reusable workflow runs ShellCheck (with .shellcheckrc) and shfmt against all .sh files. Both tools reported failures:

• ShellCheck: Multiple violations across scripts/ and src/ shell scripts (rules configured via .shellcheckrc)
• shfmt: Formatting inconsistencies in shell scripts

Acceptance Criteria

• All ShellCheck violations are resolved (per .shellcheckrc configuration)
• All shfmt formatting issues are resolved
• Bash syntax check passes for all .sh files
• Shell Lint job in PR validation passes without soft-fail: true
• Remove soft-fail: true from shell-lint in .github/workflows/pr-validation.yml

References

• PR build(ci): replace MegaLinter with per-tool GitHub Actions lint workflows #240 — MegaLinter replacement
• Issue ci(lint): replace MegaLinter with dedicated per-tool GitHub Actions workflows #235 — Parent issue