feat(pleno-vue): warning on red cars (TRU-99) (#318)

## Summary

Closes (heuristic for) **TRU-99 / SENERE 7**: warn operators in the
customer portal wash flow when a customer is flagged as a red car.

## Detection rule — heuristic, Mads to refine

The canonical rule (plate scan vs. red-car tag) is still TBD by Mads. As
a sensible default that fits the existing data model, this PR uses a
**manual customer-attribute flag**:

- If a customer has one of the configurable attribute keys set, the
warning fires. Default keys: `isRedCar`, `is_red_car`, `redCar`,
`red_car`.
- Detection is **case-insensitive** and the key list is **configurable**
(callers can override) so the rule can be tightened later without
touching the UI.
- Detection lives in `src/composables/redCarDetector.js`; reactive
loading lives in `src/composables/useRedCarWarning.js`.
- The composable reuses the existing `/customer/attributes` endpoint via
`customerAttributeService.js` — no backend change needed.

## UI

- New `RedCarWarning.vue` component renders a dismissable Buefy warning
in the vehicle step of the self-serve flow, with title + reason + care
suggestion.
- Wired into `MyWashStart.vue` via the existing `VehicleInputSection` /
`SelfServeVehicleStep` props. The composable is called with the
effective customer number (authenticated subuser or typed-in).
- Translations added in all 5 locales: `da`, `en`, `sv`, `de`, `no`
(source + regenerated runtime files).

## Tests

- 22 detector unit tests (positive, negative, case-insensitive, custom
keys, dedupe, normalisation).
- 5 i18n key presence tests across all 5 locales.
- 4 `RedCarWarning` component tests (conditional render, dismiss
wiring).

All new + existing related tests pass: `vitest run` on
`red-car-detector`, `red-car-warning-i18n`, `red-car-warning`,
`my-wash-start`, `customer-rule-registry`, `customer-rule-tooltip` →
**84/84 green**.

## Out of scope / not touched

- Backend / API: reused existing `/customer/attributes` endpoint.
- `openclaw.json`, deployment, merge — not touched (per task
constraints).
- Customer-rule registry: not added to `CUSTOMER_RULE_DEFINITIONS`
because the red-car flag is a soft warning, not a product-restriction
rule. If Mads wants it surfaced in the customer rule manager UI, that is
a follow-up.

## Files

- `src/composables/redCarDetector.js` (new)
- `src/composables/useRedCarWarning.js` (new)
- `src/components/displays/selfServe/RedCarWarning.vue` (new)
- `src/components/displays/selfServe/SelfServeVehicleStep.vue` (prop +
render)
-
`src/views/dashboards/userDashboard/wash/components/VehicleInputSection.vue`
(prop pass-through)
- `src/views/dashboards/userDashboard/wash/MyWashStart.vue` (composable
+ prop binding)
- `src/i18n/source/{da,en,sv,de,no}/phrases/compat/self_wash/index.json`
(new keys)
- `src/i18n/generated/{da,en,sv,de,no}-v2.json` (regenerated)
- `tests/unit/red-car-detector.spec.js` (new)
- `tests/unit/red-car-warning-i18n.spec.js` (new)
- `tests/unit/red-car-warning.spec.js` (new)

Refs: TRU-99

---------

Co-authored-by: Jeppe B <jeppe@copenhagentruckwash.io>
Co-authored-by: Frontend Subagent <frontend-agent@openclaw.local>
Co-authored-by: Pleno Bugfix Bot <bugfix-bot@pleno.local>

src/i18n/generated/en-v2.json

@@ -5746,6 +5746,9 @@
           "open_property_exit_gate": "@.capitalize:{'words.generated.open'} @:{'words.generated.property'} @:{'words.generated.exit'} @:{'words.generated.gate'}",
           "perform_wash": "@.capitalize:{'words.generated.perform'} @:{'words.generated.wash'}",
           "questions_answered": "@.capitalize:{'words.generated.questions'} @:{'words.generated.answered'}",
+          "red_car_warning_title": "Red car on site",
+          "red_car_warning_message": "This customer is flagged as a red car. Red paint is more prone to staining and swirls — handle with extra care.",
+          "red_car_warning_suggestion": "Suggest a gentler wash: skip high-pressure pre-wash, avoid harsh brushes, and dry with a soft microfiber.",
           "select_from_vehicles": "@.capitalize:{'words.generated.select'} {plate} @:{'words.generated.from'} @:{'words.generated.your'} @:{'words.generated.vehicles'}",
           "select_vehicle_type": "@.capitalize:{'words.generated.select'} @:{'words.generated.vehicle'} @:{'words.generated.type'}",
           "select_vehicle": "@.capitalize:{'words.generated.select'} @:{'words.generated.vehicle'}",