[META] Phase 6: Full-stack assets

## Parent

Sub-issue of https://github.com/elastic/obs-integration-team/issues/1048 (Phase 6 — Full-stack assets).

## Goal

Move beyond dashboards into broader observability assets: SLOs, Synthetics, RBAC, and remaining alert/monitor semantics.

## Target

H2 2026.

## Exit Criteria

- Each supported asset family has an explicit source/target contract.
- Unsupported asset semantics are surfaced as manual-review gaps.
- Alert rule lifecycle and enablement are documented and safe by default.

## Filing

Datadog hard-to-migrate monitors already live under https://github.com/elastic/obs-integration-team/issues/1202 (OMP #1 and its children). Grafana alert translation lives under https://github.com/elastic/obs-integration-team/issues/1201.

This phase is the remaining families that are not filed yet (SLOs, Synthetics, RBAC). Parent those here until a dedicated program exists.