L2 — Decision engine

Status: stub. Day 4 deliverable.

Two-phase decomposition (Blueprint v4.0 §4):

1. Synchronous fast path — deterministic rule evaluation only. Workers Bundled plan, p95 ≤ 10 ms, p99 ≤ 30 ms, CPU ≤ 40 ms. LLM calls are forbidden by doctrine.
2. Asynchronous deep path — Cloudflare Queue → Workers Unbound consumer (30 s CPU). Vector RAG, LLM calls, Durable Object tenant state, then the Decision Aggregator → Integrity Plane → webhook.

Sync returns one of PASS, REJECT, ESCALATE_TO_QUEUE. The latter hands work off to the async path.