chore(harness): finish remaining coord-service reporting cutover

## Context
The mandatory `pnpm harness tick` loop is now on coord-gateway (#380), but one optional reporting command and one protocol table still describe the retired service.

## Scope
- Migrate `.harness/scripts/cycle-report.ts` from `COORD_SERVICE_URL` + `/status` to coord-gateway claims/events and the GitHub work-cycle narrative source.
- Update `docs/coordination-protocol.md` task transition wording from `ack·done·recall` to the real public `ack·complete` surface, noting recall is admin-only.
- Remove remaining operational `coord-service` instructions without rewriting historical ADR context.

## Acceptance
- `pnpm harness cycle-report` succeeds with only `COORD_GATEWAY_URL`, `COORD_API_TOKEN`, `COORD_REPO`, and GitHub auth configured.
- Missing/unreachable authority remains visible and nonzero; it is never rendered as an empty healthy report.
- Focused tests cover success, auth failure, and unreachable gateway.
- `rg` finds no active operational use of `COORD_SERVICE_URL` or `COORD_SERVICE_TOKEN` outside historical records.

Start with .harness/scripts/cycle-report.ts and docs/coordination-protocol.md; trace the existing coord-gateway claims/events and GitHub work-cycle inputs, then run pnpm harness cycle-report with the documented configuration. Done means the command handles success, auth failure, and unreachable gateway visibly, focused tests cover those cases, and rg finds no active operational use of the retired environment variables outside historical records.

Written by the indexing model from the issue text.