feat(core): Gate process controls by OS support

[bigtomcat6]

Summary

• Gate process-level audio controls based on OS support so unsupported control paths are not exposed.
• Admit structurally supported native audio routes and require exactly one valid route submission for process control.
• Enforce fail-closed routing behavior when native hardware inventory is empty and preserve multi-route fail-closed startup diagnostics.
• Keep native topology diagnostics and evidence output paths stable so native validation failures are easier to triage.
• Expand native evidence tests and fixtures for multi-device route admission and parent-path preservation.

How to test

• Run the updated audio routing/evidence test targets for MacActivityCore and MacActivityApp.
• Review runtime diagnostics output for empty inventory or multi-route startup paths to confirm fail-closed behavior and route-structure validation messages.
• Manually verify OS-gated audio process controls are hidden/disabled when the host platform does not support them.

Release impact

• Type: Added
• Release note: Added OS-aware gating for process audio controls and stronger native routing admission/diagnostic behavior for multi-route setups.

Checklist

• I have seen this code, I have run this code, and I take responsibility for this code.
• PR title follows type(scope): Summary.
• Tests or a clear manual verification path are included.
• User-facing changes include release-note wording or Release impact: None.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[bigtomcat6]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🎉

Reviewed commit: 18079e53cc

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[bigtomcat6]

reviewed