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

apps/server/src/snapshot.ts

@@ -167,22 +167,29 @@ async function recognizePlate(
 ): Promise<void> {
   try {
     const result = await vision.analyze(shot.bytes, shot.contentType);
-    if (!result || !result.plate || result.lowConfidence) return; // nothing trustworthy to record
-    const plate = result.plate.text.trim().toUpperCase();
-    if (!plate) return;
+    if (!result) return;
+    // The vehicle's body type (advisory; the wash desk's category suggestion — see
+    // venue-modules.md §Vehicle category). Rides the plate's read row when there is one,
+    // else a row of its own: a car with an unreadable plate is still a car of some class.
+    const vehicle = result.vehicle
+      ? { bodyType: result.vehicle.bodyType, bodyConfidence: result.vehicle.confidence }
+      : {};
+    const plate = !result.plate || result.lowConfidence ? "" : result.plate.text.trim().toUpperCase();
+    if (!plate && !result.vehicle) return; // nothing trustworthy to record
     db.insert(deviceEventsTable)
       .values({
         id: randomUUID(),
         deviceId,
         category: "camera",
         kind: "read",
-        // `identity` ties the plate to the session; `snapshotId` to the evidence image.
+        // `identity` ties the read to the session; `snapshotId` to the evidence image.
         detail: {
           identity,
           direction,
-          plate,
-          confidence: result.plate.confidence,
-          region: result.plate.region ?? null,
+          ...(plate
+            ? { plate, confidence: result.plate!.confidence, region: result.plate!.region ?? null }
+            : {}),
+          ...vehicle,
           modelVersion: result.modelVersion,
           snapshotId,
           source: "entry-exit-snapshot",
@@ -190,7 +197,9 @@ async function recognizePlate(
         occurredAt: new Date().toISOString(),
       })
       .run();
-    logger.info(`anpr plate '${plate}' (${result.plate.confidence.toFixed(3)}) for ${identity}`);
+    if (result.vehicle) logger.info(`vision vehicle '${result.vehicle.bodyType}' (${result.vehicle.confidence.toFixed(3)}) for ${identity}`);
+    if (!plate) return;
+    logger.info(`anpr plate '${plate}' (${result.plate!.confidence.toFixed(3)}) for ${identity}`);
     // The session's entry/exit event already shipped without this (async) plate — tell the
     // booth so it backfills the plate badge in place (no refresh). Advisory; ledger untouched.
     deviceEvents.emitPlateRecognized({ identity, plate, direction });