feat(deployments): cancel superseded deployments when a newer one is queued

database/migrations/2026_11_03_072701_add_auto_cancel_superseded_deployments.php

@@ -0,0 +1,37 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('application_settings', function (Blueprint $table) {
+            if (! Schema::hasColumn('application_settings', 'is_auto_cancel_queued_deployments_enabled')) {
+                $table->boolean('is_auto_cancel_queued_deployments_enabled')->default(true);
+            }
+            if (! Schema::hasColumn('application_settings', 'is_auto_cancel_building_deployments_enabled')) {
+                $table->boolean('is_auto_cancel_building_deployments_enabled')->default(false);
+            }
+        });
+
+        if (! Schema::hasColumn('application_deployment_queues', 'deploy_started_at')) {
+            Schema::table('application_deployment_queues', function (Blueprint $table) {
+                $table->timestamp('deploy_started_at')->nullable();
+            });
+        }
+    }
+
+    public function down(): void
+    {
+        Schema::table('application_settings', function (Blueprint $table) {
+            $table->dropColumn(['is_auto_cancel_queued_deployments_enabled', 'is_auto_cancel_building_deployments_enabled']);
+        });
+
+        Schema::table('application_deployment_queues', function (Blueprint $table) {
+            $table->dropColumn('deploy_started_at');
+        });
+    }
+};