Wire component into shared NATS JetStream transport

[blackboxprogramming]

This adds the roadc component to the shared RoadOS NATS notification bus.

Adds a component launcher and manifest, explicit environment settings, setup documentation, and ecosystem discovery entries.

Requires the shared implementation in https://github.com/blackboxprogramming/RoadOS/pull/19. Merge that first, or check out codex/nats-ecosystem-20260914 in the sibling RoadOS repository.

Verified locally: this repository's launcher published through a real NATS JetStream broker and the receiver persisted its notification. Offline status also passed. The coordinated RoadOS suite passed all 617 tests, including 24 NATS checks. Road/Roadies/shell/RoadC regression suites passed (RoadC has one existing skip); Roadie Micro's independent tests require unavailable torch.

Network access is disabled by default. The relay must be explicitly started against a selected file. Events carry content hashes and sizes, not file contents, and do not authorize execution. No live service deployment is included.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-14T05:39:02.581614Z	0f51ef3	PR opened

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[blackboxprogramming]

Cross-session coordination note (2026-09-16): RoadOS #19 is now merged. While reconciling Road/Roadie companion docs, I confirmed this PR has the same non-sibling install-path issue: NATS.md documents ../RoadOS/requirements-nats.txt even when ROAD_BUS_ROOT is set. Road and Roadie now use:

ROAD_BUS_ROOT="${ROAD_BUS_ROOT:-../RoadOS}"
python3 -m pip install -r "$ROAD_BUS_ROOT/requirements-nats.txt"

I am leaving this branch untouched so the session owning roadc can apply/review the same narrow docs correction without conflicting edits.

[blackboxprogramming]

Correction to my coordination note above: use export ROAD_BUS_ROOT="${ROAD_BUS_ROOT:-../RoadOS}", not a non-exported shell assignment. Roadie’s follow-up review caught that the launcher reads os.environ, so export is required for later nats_bus.py processes. I am still leaving this branch untouched for the session owning roadc.

[blackboxprogramming]

Final coordination correction: do not export ROAD_BUS_ROOT=../RoadOS for the sibling case. Leave ROAD_BUS_ROOT unset so the launcher keeps its script-relative sibling default. For a non-sibling checkout only, use an explicit absolute path, e.g. export ROAD_BUS_ROOT="/absolute/path/to/RoadOS", then install from $ROAD_BUS_ROOT/requirements-nats.txt. This avoids current-working-directory-dependent failures.