🛡️ Sentinel: [HIGH] Fix command option injection in Git calls

[tamld]

• 🚨 Severity: HIGH
• 💡 Vulnerability: Calls to exec.Command("git", ...) appended paths or branch names without explicitly indicating the end of options using --. If an untrusted path or branch name starts with -, Git parses it as an option, which can lead to command option injection.
• 🎯 Impact: An attacker could potentially inject arbitrary command-line options into git executions (like --force, --exec, or others) if they can control the branch or path name, leading to unauthorized operations or potential RCE in some contexts.
• 🔧 Fix: Added -- to separate the git subcommands from the user-provided variables (specifically deliverableDir and taskID inside cmd/g8s/deliver.go) ensuring they are strictly treated as positional arguments and not flags.
• ✅ Verification: Ran gofmt, local build (go build ./...), and full test suite (CGO_ENABLED=1 go test -v -race ./...) to ensure that this fix does not introduce side effects and passes all current assertions.

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PR created automatically by Jules for task 11627232452063960269 started by @tamld

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