Implement EnsureUserHasWorkspace Trait and Integrate into Controllers… (#741)

* Implement EnsureUserHasWorkspace Trait and Integrate into Controllers and Jobs

- Introduced the EnsureUserHasWorkspace trait to ensure users have at least one workspace when they are detached from a workspace.
- Integrated the trait into WorkspaceUserController to enforce workspace checks during user detachment.
- Updated RemoveWorkspaceGuests job to utilize the new trait for ensuring users have a workspace after detachment.
- Modified UserWorkspace model to call the ensureUserHasWorkspace method upon deletion, maintaining workspace integrity.

These changes enhance user management by ensuring that users always have a workspace, improving overall application stability.

* Add test

---------

Co-authored-by: Julien Nahum <julien@nahum.net>

api/app/Traits/EnsureUserHasWorkspace.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Traits;
+
+use App\Models\User;
+use App\Models\Workspace;
+use Illuminate\Support\Facades\Log;
+
+trait EnsureUserHasWorkspace
+{
+    /**
+     * Ensure a user has at least one workspace.
+     * If they don't, create a new workspace for them.
+     */
+    protected function ensureUserHasWorkspace(User $user): void
+    {
+        if ($user->workspaces()->count() === 0) {
+            Log::info('Creating new workspace for user with no workspaces', [
+                'user_id' => $user->id,
+                'user_email' => $user->email,
+            ]);
+
+            $newWorkspace = Workspace::create([
+                'name' => 'My Workspace',
+            ]);
+
+            $user->workspaces()->sync([
+                $newWorkspace->id => [
+                    'role' => 'admin',
+                ],
+            ], false);
+        }
+    }
+}