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

database/factories/TownFactory.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Database\Factories;
+
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/**
+ * @extends \Illuminate\Database\Eloquent\Factories\Factory<\App\Models\Town>
+ */
+class TownFactory extends Factory
+{
+    /**
+     * Define the model's default state.
+     *
+     * @return array<string, mixed>
+     */
+    public function definition(): array
+    {
+        return [
+            //
+        ];
+    }
+}