Preview Gate (Tier 1)

This is the deterministic blast-radius calculator that runs beforeany high-risk action reaches an approver. It consults four read-only preview sources in parallel — AWX --check, SSM dry-run, graph-impact traversal, and static analysis— and returns predicted state diffs, downstream impact, warnings, and a worst-warning summary. Nothing executes.

Per the SyRS GR-002 gate-selection rule and §7.3 lifecycle, the BlastRadiusReport is informational metadata attached to the gate — it does not change approval logic. Tier 2 (full digital-twin rehearsal) is deferred per epic afw-l44.