Add a docker command runner helper

[alxdca]

This PR is part of a stack created with Aviator. feat: get chain contract versions #687 ➡️ Add a docker command runner helper #685 main

Summary

• add a runDockerCommand helper that wraps docker run --rm
• support passing command args, an optional entrypoint, and environment variables
• return structured execution metadata including argv, stdout, stderr, and exit code

Why / Context

• upcoming SDK flows need a reusable way to invoke Docker-based tooling
• environment values should be passed to the child process without leaking secret contents into logged argv or error metadata
• centralizing the Docker invocation logic makes higher-level Docker-backed features easier to implement and test

Test Plan

• Run the unit test suite covering src/runDockerCommand.unit.test.ts
• Verify the helper correctly passes env var names without exposing env var values in argv or error metadata
• Smoke test one Docker-backed call path that uses this helper

Validation evidence

• No test, lint, or build results were gathered for this draft
• Evidence used for the summary: current branch diff/commit metadata only