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/Enums/AustralianState.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace App\Enums;
+
+enum AustralianState: int
+{
+    case NSW = 1;
+    case VIC = 2;
+    case QLD = 3;
+    case SA = 4;
+    case WA = 5;
+    case TAS = 6;
+    case NT = 7;
+    case ACT = 8;
+
+    public function label(): string
+    {
+        return match ($this) {
+            self::NSW => 'New South Wales',
+            self::VIC => 'Victoria',
+            self::QLD => 'Queensland',
+            self::SA => 'South Australia',
+            self::WA => 'Western Australia',
+            self::TAS => 'Tasmania',
+            self::NT => 'Northern Territory',
+            self::ACT => 'Australian Capital Territory',
+        };
+    }
+
+    public function abbreviation(): string
+    {
+        return match ($this) {
+            self::NSW => 'NSW',
+            self::VIC => 'VIC',
+            self::QLD => 'QLD',
+            self::SA => 'SA',
+            self::WA => 'WA',
+            self::TAS => 'TAS',
+            self::NT => 'NT',
+            self::ACT => 'ACT',
+        };
+    }
+}