fix(config): isolate environment overrides

[linkdata]

Summary

• apply the configured Viper environment prefix before AutomaticEnv
• keep unprefixed environment variables from overriding config keys
• add prefixed and unprefixed env override coverage

Tests

• go test ./pkg/cmd ./...

[coderabbitai]

Warning

Rate limit exceeded

@linkdata has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 59 minutes and 17 seconds before requesting another review.

To keep reviews running without waiting, you can enable usage-based add-on for your organization. This allows additional reviews beyond the hourly cap. Account admins can enable it under billing.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: fcfd4ffb-00d7-4a93-b56d-7ee9e467da4f

📥 Commits

Reviewing files that changed from the base of the PR and between b615285 and 7d510e0.

📒 Files selected for processing (2)

• pkg/cmd/root.go
• pkg/cmd/root_test.go

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Review rate limit: 0/1 reviews remaining, refill in 59 minutes and 17 seconds.}

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[linkdata]

Additional context from comment files

These notes were split from the local markdown comment files and attached here because they describe this PR's change.

Config Env Isolation

• Bug: Viper accepted unprefixed environment variables, so unrelated ambient variables such as DEBUG=release were treated as EDM config.
• Impact: Startup could fail during config unmarshalling before any runtime work began, even when the config file and flags were valid.
• Fix: Environment overrides now require the DNSTAPIR_EDM_ prefix and map hyphenated config keys to underscore-separated environment keys.
• Reasoning: Prefixed environment variables preserve intentional env-based config while preventing collisions with common shell or build environment variables.
• Tests: Added command-package tests proving DEBUG=release is ignored and DNSTAPIR_EDM_DEBUG=true still overrides debug = false.