test(factories): add missing model factories for app test suite

Enable `HasFactory` on `Environment`, `Project`, `ScheduledTask`, and
`StandaloneDocker`, and add dedicated factories for related models to
stabilize feature/unit tests.

Also bump `visus/cuid2` to `^6.0` and refresh `composer.lock` with the
resulting dependency updates.

database/factories/ProjectFactory.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace Database\Factories;
+
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+class ProjectFactory extends Factory
+{
+    public function definition(): array
+    {
+        return [
+            'name' => fake()->unique()->company(),
+            'team_id' => 1,
+        ];
+    }
+}