feat(carwash): advisory vehicle category from the entry camera — mapping, pre-select, downgrade flag

The app plumbing for venue-modules.md §"Vehicle category from vision"; the model is the
open half (no bundled recognizer emits body_type yet, so the desk shows nothing until
phase A lands in the vision service).

- Shared: VEHICLE_CLASSES vocabulary, VehicleRead, CARWASH_VISION_THRESHOLD_DEFAULT,
  reason code carwash.categoryDowngrade; settings/order/lookup views carry the read.
- Vision contract: /analyze vehicle.body_type + confidence (service schema); the Node
  client normalises to the vocabulary and drops the rest.
- Record: snapshot.ts stores the read in the plate's device_events row (or its own when
  the plate was unreadable); vehicleForIdentity() resolves it like the plate.
- Car wash: carwash_categories.vision_classes (site mapping "car, sedan → Vetura"),
  carwash_config.vision_threshold (signed config_change when it moves), four vision
  columns on orders — migration 0030. Lookup returns vision + suggestedCategoryId.
- Desk pre-selects the mapped category and shows the read + snapshot thumbnail; Setup
  offers class chips per category and the threshold. Operator decides.
- Flag: a read at/above the threshold whose mapped category prices HIGHER than the chosen
  one signs one `anomaly` (both categories/prices, operator, snapshot) and stores its id on
  the order. Equal/upgrade/unsure/unmapped → nothing. Recorded only, never blocks, no
  reason prompt (user, 2026-09-06).

Tests in carwash.test.ts; wiki venue-modules (As built), opencv-anpr-service, log.

Claude-Session: https://claude.ai/code/session_01FWncR69HgGPuei1dLrW3cU

wiki/entities/opencv-anpr-service.md

@@ -248,3 +248,12 @@ service's `/health` each tick and shows a **"Vision" chip** in the booth footer
   ([[bom]], [[open-questions]]).
 - Per-camera **opt-in** — ✅ **built**: `config.anpr === true` enables ANPR on a camera (set via the
   SetupWizard checkbox); ANPR then runs on that camera's entry/exit snapshot.
+
+## Vehicle body type (advisory) — contract only, 2026-09-06
+
+`/analyze` may now populate `vehicle.body_type` + `vehicle.confidence` from the shared vocabulary
+(car, sedan, hatchback, suv, minivan, pickup, van, truck, bus, motorcycle). Node records it beside
+the plate and the Car Wash desk pre-selects the category the site maps it to; the operator
+decides, a confident downgrade is flagged, nothing is gated on it. No bundled recognizer emits
+it yet — see [[venue-modules]] §Vehicle category from vision for the model plan (COCO detector
+first, body-type classifier on own frames second).