Test: cover SEMBLEOPS_CONFIG path overrides

[TheDThompsonDev]

Why this matters

Operators can override the node config path, but the behavior and its failure modes have no direct test coverage.

Scope

• Create temporary valid node and personas YAML fixtures.
• Assert that SEMBLEOPS_CONFIG selects the alternate node file.
• Assert that personas still load from the root config directory.
• Restore the process environment after each test.

Suggested starting points

• src/config/load.ts
• src/config/schema.ts
• test

Acceptance criteria

• Tests do not modify checked-in config files.
• Environment state is restored even when an assertion fails.
• A missing override path produces an expected error.

Out of scope

• Changing config precedence.
• Adding new environment variables.

How to verify

• Run npm test individually and as part of the full suite to catch environment leakage.

New contributor notes

Please comment before starting so maintainers can confirm nobody else is working on it. Use only synthetic examples and never commit real API keys, tokens, private content, database files, or deployment credentials.