fix(models): replace forceFill/forceCreate with fill/create and add fillable guards

Replace all uses of `forceFill`, `forceCreate`, and `forceFill` with their
non-force equivalents across models, actions, controllers, and Livewire
components. Add explicit `$fillable` arrays to all affected Eloquent models
to enforce mass assignment protection.

Add ModelFillableCreationTest and ModelFillableRegressionTest to verify that
model creation respects fillable constraints and prevent regressions.

app/Http/Controllers/Api/ProjectController.php

@@ -258,7 +258,7 @@ class ProjectController extends Controller
             ], 422);
         }
 
-        $project = Project::forceCreate([
+        $project = Project::create([
             'name' => $request->name,
             'description' => $request->description,
             'team_id' => $teamId,