fix(config): fall back after scoped secret miss

[tianma-if]

Summary

• fix get_env_value_prefer_dotenv() so a scoped secret miss can still read os.environ in non-multiplex deployments
• keep multiplexed profile scopes authoritative so a missing profile secret does not leak a process-global provider key
• add regression coverage for the BWS/cron-style scoped miss and the multiplex isolation case

Fixes #58100.

Test plan

• source .venv/bin/activate && pytest tests/hermes_cli/test_config.py -q -k "TestGetEnvValuePreferDotenv"
• source .venv/bin/activate && pytest tests/hermes_cli/test_xiaomi_provider.py tests/hermes_cli/test_api_key_providers.py -q -k "xiaomi or env or credential or provider"
• git diff --check

[tonydwb]

Verdict: Approved (read-only token - formal approval deferred)

Small, well-scoped fix. No concerns.

[tonydwb]

Code Review Summary

Verdict: Approved (LGTM)

Falls back after scoped secret miss. Improves config robustness.

What Looks Good

• Targeted fix
• No security concerns
• No debug artifacts

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Reviewed by Hermes Agent

[teknium1]

Thanks for the narrowly scoped regression fix. The non-multiplex behavior is real on current main: hermes_cli/config.py:7873 directly returns a scoped miss, and the added tests cover the safe fallback plus the multiplex isolation boundary.

Problems

• Fixes #58100 overstates completion. The new multiplex-active branch intentionally returns None; agent/secret_scope.py:145-160 confirms a scoped miss must not read process-global environment values. The cron-specific [Bug]: get_env_value_prefer_dotenv returns None when get_secret returns None instead of falling through to os.environ #58100 discussion reports BWS credentials in that multiplex/profile-scoped path, which this PR leaves unresolved. Open fix(secrets): scope BWS-injected provider keys #58111 proposes same-home scope propagation for that case.

Suggested changes

• Mark this as related to [Bug]: get_env_value_prefer_dotenv returns None when get_secret returns None instead of falling through to os.environ #58100 rather than closing it, unless the broader multiplex BWS path is addressed through the scoped-secret approach.

Automated hermes-sweeper review.

[teknium1]

Closing as superseded: commit c758ded (fix(secrets): fall back to os.environ on scope miss when multiplexing is off, merged Jul 20) implemented exactly this PR's semantic — scope-miss environ fallback gated on the multiplex flag — but centrally inside agent.secret_scope.get_secret rather than per-caller, and get_env_value_prefer_dotenv now routes through it. Your linked issue #58100 is closed COMPLETED by that commit. Thanks @tianma-if — the diagnosis (BWS-injected keys invisible under an unconditionally-installed scope) was exactly right, and the mode-conditional rule you proposed is now the documented design.