feat: transport incidents with truck number support

- DB: trucks table + incidents.truck_id FK + transport enum value
- Validation: transport type requires truck_id
- Create API: validates truck exists/active, persists truck_id
- Report form: truck dropdown shown when type=transport (required)
- Admin: TruckManager CRUD + /api/admin/trucks route
- Detail: trucks join surfaced in incident-detail + detail page query
- Inbox (HSE + supervisor): truck filter, transport in TYPE_OPTIONS,
  fixed stale enum values (dropped dangerous_occurrence/mhe_asset/occupational_disease)
- List: transport label + truck number badge in rows
- i18n: transport + truckLabel/truckPlaceholder in en/ms/zh

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CPf5Rc8QPx6V8KLEEgfKEQ

messages/ms.json

@@ -16,7 +16,9 @@
     "qualityScoreLabel": "Kualiti laporan — {score}/10",
     "errorGeneric": "Berlaku ralat. Sila cuba lagi.",
     "savedOffline": "Laporan disimpan. Ia akan dihantar secara automatik apabila anda dalam talian semula.",
-    "offlineBanner": "Anda tiada sambungan. Laporan anda akan disimpan dan dihantar apabila disambungkan semula."
+    "offlineBanner": "Anda tiada sambungan. Laporan anda akan disimpan dan dihantar apabila disambungkan semula.",
+    "truckLabel": "Trak",
+    "truckPlaceholder": "Pilih trak…"
   },
   "IncidentType": {
     "injury": "Kecederaan / Perubatan",
@@ -25,7 +27,8 @@
     "asset_damage": "Kerosakan Aset / Peralatan",
     "environmental": "Insiden Alam Sekitar",
     "security": "Insiden Keselamatan",
-    "fire": "Kebakaran / Kecemasan"
+    "fire": "Kebakaran / Kecemasan",
+    "transport": "Pengangkutan / Kenderaan"
   },
   "MedicalStatus": {
     "none": "Tiada rawatan diperlukan",