Add nightly town sync from ArcGIS API with autocomplete

- Add towns table with town_pid, town_name, state, population, town_class, date_retired
- Add AustralianState enum with label and abbreviation helpers
- Add Town model with active() and search() scopes
- Add SyncTowns job that paginates ArcGIS API and upserts all 1977 towns
- Schedule SyncTowns to run nightly at 02:00
- Add /towns/search endpoint returning JSON suggestions filtered by name and state
- Add Alpine-powered autocomplete on origin/destination fields in create form
- Add state filter dropdown in journeys card header to narrow autocomplete results

app/Models/Town.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace App\Models;
+
+use App\Enums\AustralianState;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+
+class Town extends Model
+{
+    /** @use HasFactory<\Database\Factories\TownFactory> */
+    use HasFactory;
+
+    protected $fillable = [
+        'town_pid',
+        'town_name',
+        'state',
+        'population',
+        'town_class',
+        'date_retired',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'state' => AustralianState::class,
+            'date_retired' => 'datetime',
+        ];
+    }
+
+    public function scopeActive(Builder $query): void
+    {
+        $query->whereNull('date_retired');
+    }
+
+    public function scopeSearch(Builder $query, string $term): void
+    {
+        $query->where('town_name', 'like', $term.'%');
+    }
+}