docs(vrs): require quiet evented coordination

[myobie]

Summary

• Add R22. A network stays quiet while useful work continues.
• Start coordination only after an inbox DING, a durable failure, a real blocker, a completion or decision handoff, or a declared schedule with a name.
• Continue until the need is resolved or handed off. Do not replace this work with repeated status messages or peer polling.
• Let normal supervisors handle failures and blocked work. A custom supervisor can require more coordination. st2 does not define or require CoS.
• Keep independent host-local work available when transport is lost.

Scope

This docs-only change uses the existing root VRS surface. It changes docs/vrs/requirements.md and docs/vrs/spec.md. The final delta is 37 added lines: 10 in requirements and 27 in the specification. The specification links to the existing DING requirements. It leaves the DQ1 schedule grammar open. It adds no runtime or sub-VRS.

Rewrite from 7f9ae0d

The rewrite replaces the event table and specialist terms with short sentences and a four-item list. It keeps the R22 event boundary, named schedules, outcome-focused follow-through, normal supervisor scope, optional custom supervisor behavior, CoS boundary, and host-local autonomy.

Verification at fc60574305c062cea04ad1cc48aa9f2194d84511

• R22 requirement and specification anchors are unique: PASS
• DING requirements link target exists: PASS
• Locked specialist terms are absent: PASS
• New R22 text has no line longer than 100 characters: PASS
• cargo test --test invariants -- --test-threads=1: PASS (1/1)
• cargo test --doc --workspace: PASS
• git diff --check: PASS
• Hosted Nix: PASS — run 30634571878 / job 91168804854

This PR stays draft, open, unmerged, and reviewer-free. Nathan must review this exact final head before merge. No live catalog, supervisor, service, inbox, or PTY state was mutated.

[myobie]

Nathan approved exact head fc60574305c062cea04ad1cc48aa9f2194d84511. I will change this PR from draft to ready and merge it. No state restoration is planned.