feat(fleet): validate vehicle plate numbers against a letters-and-digits format

Plate, power-plate and trailer accepted any free text — a vehicle could be
saved with a plate of "assadasd". They must be letters, a hyphen, then digits,
like ET-9875 or AA-8642.

The server now enforces it on CreateVehicleDto (and UpdateVehicleDto via
PartialType): each plate is trimmed and upper-cased, then matched against
^[A-Z]{2,3}-\d{2,6}$, so "et-9875" is accepted and stored as ET-9875 while an
empty optional trailer/power plate still passes.

The fleet form gains the same check inline: FleetFormFieldDef takes an optional
pattern, the dialog tests it on submit against the upper-cased value, and the
vehicle config points plate and trailer at a regex that mirrors the server's.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/edr-freight-web/backoffice/src/pages/fleet/config/resources.ts

@@ -69,6 +69,11 @@ export interface FleetFormFieldDef extends FormFieldDef {
    * (e.g. a license expiry); "past" (default) = cannot be in the future.
    */
   dateBound?: "past" | "future";
+  /**
+   * Format the value must match, checked on submit. The value is upper-cased and
+   * trimmed before the test, matching the server. Empty optional fields skip it.
+   */
+  pattern?: { regex: RegExp; message: string; uppercase?: boolean };
 }
 
 export interface FleetListFilterDef {

apps/edr-freight-web/backoffice/src/pages/fleet/config/vehicles.ts

@@ -1,5 +1,15 @@
 import type { FleetResourceConfig } from "./resources";
 
+/**
+ * A plate is two or three letters, a hyphen, then two to six digits — ET-9875,
+ * AA-8642. Mirrors VEHICLE_PLATE_REGEX on the API so the form and the server
+ * agree on what a plate looks like.
+ */
+const PLATE_PATTERN = {
+  regex: /^[A-Z]{2,3}-\d{2,6}$/,
+  message: "Use letters and numbers like ET-9875 or AA-8642",
+};
+
 const VEHICLE_TYPE_OPTIONS = [
   { label: "Truck", value: "TRUCK" },
   { label: "Van", value: "VAN" },
@@ -77,9 +87,9 @@ export const vehiclesConfig: FleetResourceConfig = {
   ],
   formFields: [
     { name: "code", label: "Code", type: "text" },
-    { name: "plateNumber", label: "Power Plate No", type: "text", required: true },
+    { name: "plateNumber", label: "Power Plate No", type: "text", required: true, pattern: PLATE_PATTERN },
     // { name: "powerPlateNo", label: "Power Plate No", type: "text" },
-    { name: "trailerPlateNo", label: "Trailer Plate No", type: "text" },
+    { name: "trailerPlateNo", label: "Trailer Plate No", type: "text", pattern: PLATE_PATTERN },
     { name: "vehicleType", label: "Vehicle Type", type: "select", required: true, options: VEHICLE_TYPE_OPTIONS },
     { name: "manufacturer", label: "Manufacturer", type: "text", required: true },
     { name: "model", label: "Model", type: "text", required: true },