Add Popular Routes

Curated from/to destination pairs for marketing content, editable via a
Filament resource and served publicly (no auth, IP-throttled like CMS
pages) through GET /api/v1/popular-routes. The API response trims each
nested destination down to id/name/mm_name rather than the full catalog
resource.

app-modules/routing/database/migrations/2026_08_28_000000_create_popular_routes_table.php

@@ -0,0 +1,34 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('popular_routes', function (Blueprint $table) {
+            $table->id();
+            $table->foreignId('from_destination_id')->constrained('destinations')->cascadeOnDelete();
+            $table->foreignId('to_destination_id')->constrained('destinations')->cascadeOnDelete();
+            $table->text('description')->nullable();
+            $table->text('mm_description')->nullable();
+            $table->boolean('is_active')->default(true);
+            $table->timestamps();
+
+            $table->unique(['from_destination_id', 'to_destination_id']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('popular_routes');
+    }
+};