feat(inventory): track administrative entry reservations

database/migrations/2026_09_24_000000_add_administrative_entry_reservation_stock.php

@@ -0,0 +1,43 @@
+<?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('inventories', function (Blueprint $table): void {
+            $table->unsignedInteger('entry_reserved_stock')->default(0);
+        });
+        Schema::create('desfile_reservation_batches', function (Blueprint $table): void {
+            $table->id();
+            $table->foreignId('user_id')->constrained('users')->restrictOnDelete();
+            $table->string('tenant_code');
+            $table->uuid('idempotency_key');
+            $table->string('request_hash', 64);
+            $table->timestamps();
+            $table->unique(['user_id', 'idempotency_key']);
+        });
+        Schema::table('desfile_entry_reservations', function (Blueprint $table): void {
+            $table->foreignId('batch_id')->nullable()->constrained('desfile_reservation_batches')->restrictOnDelete();
+            $table->foreignId('ticket_id')->nullable()->unique()->constrained('tickets')->restrictOnDelete();
+            $table->foreignId('inventory_id')->nullable()->constrained('inventories')->restrictOnDelete();
+        });
+        // Legacy reservations remain excluded by visibleVariants(). Their past stock
+        // movements cannot be inferred safely; only new reservations use this counter.
+    }
+
+    public function down(): void
+    {
+        Schema::table('desfile_entry_reservations', function (Blueprint $table): void {
+            $table->dropConstrainedForeignId('batch_id');
+            $table->dropUnique(['ticket_id']);
+            $table->dropConstrainedForeignId('ticket_id');
+            $table->dropConstrainedForeignId('inventory_id');
+        });
+        Schema::dropIfExists('desfile_reservation_batches');
+        Schema::table('inventories', fn (Blueprint $table) => $table->dropColumn('entry_reserved_stock'));
+    }
+};