docs(runbook §4.5): refresh alerting forward-pointer (REQ-INB-30)

The runbook §4.5 "Forward-pointer" paragraph (lines 285-289)
said "Alerting is out of scope for v1.1; the alert layer is
the next v1.2 deliverable." v1.2 has shipped (tag v1.2.0 on
63c0f59) and was a 0/1 disposition — no alerting deliverable
landed. The forward-pointer was stale.

This commit updates the paragraph to reflect v1.3 reality:
alerting remains out of scope; v1.2 closed on 0/1; the
alert layer is the next v1.x candidate cycle to re-evaluate.
The metrics substrate (REQ-INB-23) is referenced as the
current observability surface. The rest of §4.5 (the
metrics tail snippet at lines 280-283, the opt-out block
at 291-294) is unchanged.

---ci---
project: inboxos
phase: 1
milestone: v1.3
status: execute
tasks_completed: [T2.2]
candidates_closed: [REQ-INB-30]
files_touched:
  - docs/operations-runbook.md (1 paragraph, lines 285-289, 5 lines)
---/ci---

docs/operations-runbook.md

@@ -282,11 +282,14 @@ cat pipelines/_artifacts/live-metrics-*.jsonl \
     | jq -c '{ts, run_id, counters}'
 ```
 
-**Forward-pointer.** Alerting is **out of scope** for v1.1; the
-runbook does not include alert rules (this is a v1.2 candidate
-per `.ciagent/inboxos/ideation/v1.1-candidates.md` Tier 2 T2-D).
-The metrics file is the substrate; the alert layer is the next
-v1.2 deliverable.
+**Forward-pointer.** Alerting is **out of scope** for v1.3. v1.2
+closed on a 0/1 ideation disposition (no candidates accepted) per
+`.ciagent/inboxos/CI-LOG.md`, so the v1.1 forward-pointer to a
+v1.2 alerting deliverable is now stale. The metrics file is the
+substrate; the alert layer is the next v1.x candidate cycle to
+re-evaluate. In the meantime the runbook §4 observability surface
+is logs-only, with `pipelines/_metrics/emit.py` emitting a per-run
+`metrics.jsonl` (REQ-INB-23) for offline postmortem.
 
 **Opt-out.** Set `LLM_METRICS_ENABLED=false` in the pipeline env
 to skip the `time.monotonic()` wrapping around the LLM HTTP POST.