fixed build system not returning docker command

[aolgeirson]

Changes

ner build and ner test now return the exit code of the docker command as opposed to just 0

Notes

The rationale for this change was to allow command chaning such as ner build && ner flash

Test Cases

• ner build on a functional Cerberus-2.0 returns 0
• ner build on a broken Cerberus-2.0 returns the error code of the compiler

To Do

This is a minor change that shouldn't require continuing effort

Checklist

• No merge conflicts
• All checks passing
• Remove any non-applicable sections of this template
• Assign the PR to yourself
• Request reviewers & ping on Slack
• PR is linked to the ticket (fill in the closes line below)

Closes #364

[Copilot]

Pull request overview

Updates the ner build wrapper so failures inside Docker propagate back to the user’s shell, enabling reliable command chaining (e.g., ner build && ner flash) and addressing Issue #364.

Changes:

• Capture docker compose run exit codes during ner build and exit non-zero on failure.
• Refactor run_command() / run_command_docker() to return command return codes (intended behavior).

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[dnakhooda]

lgtm...