Add reproducible production media worker

[jerome-queck]

Closes #128

Summary

• add one tracked production worker and launchd template for all enabled courses/providers
• produce truthful run-wide verdicts and non-zero exits for red/incomplete work
• revalidate runtime manifests and portable external tools before work
• make unsupported work terminal, preserve reconstructible direct paths, and isolate CLI tests from Owner configuration

Verification

• npm test — 386/386 pass
• npm run lint
• npm run format:check
• current five-artifact runtime manifest plus ffprobe/yt-dlp preflight verified read-only
• Standards review: pass, 0 findings
• Spec review: pass, 0 findings

Not doing

Not doing — #128, "Pilot unsupported appearances have an explicit terminal policy, and supported pilot work is either completed or explicitly left as accepted red/yellow work with evidence.": unsupported work is terminal in code, but draining or accepting the current pilot queue is Owner-run evidence retained by #129.

Not doing — #128, "A controlled Owner-run capture rehearsal documents whether browser audio capture works; two-times playback remains disabled unless its comparison evidence is complete and intelligible.": this human-only rehearsal remains in #129; 2x stays disabled.

Not doing — #128, "A real overnight/manual rehearsal confirms aggregate digest, process exit status, per-course status documents, checkpoints, and artifact paths.": this Owner-run validation remains in #129.

#128 — Make the recording media workflow reproducible, truthful, and operationally complete: 8 of 11 criteria delivered, nothing beyond the brief.

⬜ Not delivered — pilot supported work is completed or explicitly accepted red/yellow. Running the worker spends the Owner session and local media runtime; #129 retains the Owner-run decision and evidence. Say the word and I will continue it there.

⬜ Not delivered — controlled browser-audio capture rehearsal. This is explicitly human-only in #129; 2x remains disabled. Say the word and I will continue it there.

⬜ Not delivered — real overnight/manual rehearsal of digest, exit, statuses, checkpoints, and artifact paths. This is explicitly Owner-run in #129. Say the word and I will continue it there.

Everything else is ticked on the issue and in this PR.

Assisted-by: GPT-5
Co-authored-by: Codex noreply@openai.com