feat(admin/trips): surface dumpsite release records in trip detail panel

- Eager-load dumpsiteReleases.dumpsite + dumpsiteReleases.releasedByDriver
  in AdminTripController::show()
- Add releases[] array to TripResource via whenLoaded('dumpsiteReleases')
  - Fields: weight_kg, released_at, dumpsite_name, driver_name,
    gate_pass_number, dumpsite_attendant, notes
- Admin Trips detail panel now shows a 'Dumpsite Releases' section
  below the timeline with per-release cards
- Load row updated to show release count e.g. '450 kg (2 releases)'

app/Http/Controllers/Api/V1/Admin/AdminTripController.php

@@ -99,6 +99,7 @@ class AdminTripController extends ApiController
         $trip->load([
             'route', 'team.driver', 'team.scanner', 'truck', 'dumpsite',
             'stops.dropOffPoint', 'timelineEvents.recordedBy',
+            'dumpsiteReleases.dumpsite', 'dumpsiteReleases.releasedByDriver',
         ]);
 
         return $this->ok(new TripResource($trip));