feat: enable category tree for all users, remove flag (#488)

## Summary
Removes the `CategoryTree` Pennant feature flag so the parent/child
category tree UI is active for all existing and new users.

## Changes
- Delete `app/Features/CategoryTree.php` (flag resolved `false`).
- `CategoryController` — drop `Feature`/`CategoryTreeFeature` imports
and the `categoryTreeEnabled` Inertia prop.
- `parent-category-field.tsx` — remove the `usePage` flag read and `if
(!enabled) return null` gate; the parent field now always renders.

## Testing
- `vendor/bin/pint --dirty` — pass
- `bun run lint` — clean (1 pre-existing unrelated warning in
`chart.tsx`)
- `php artisan test tests/Feature/Settings/CategoryTreeTest.php` — 11
passed
- `php artisan test tests/Feature/Settings/CategoryTest.php` — 32 passed

app/Features/CategoryTree.php

@@ -1,23 +0,0 @@
-<?php
-
-namespace App\Features;
-
-use App\Models\User;
-
-/**
- * Gates the parent/child category tree UI for gradual rollout. The backend
- * always understands nesting; this flag only controls whether users can create
- * and manage nested categories from the interface.
- *
- * @api
- */
-class CategoryTree
-{
-    /**
-     * Resolve the feature's initial value.
-     */
-    public function resolve(?User $user): bool
-    {
-        return false;
-    }
-}

app/Http/Controllers/Settings/CategoryController.php

@@ -3,7 +3,6 @@
 namespace App\Http\Controllers\Settings;
 
 use App\Enums\CategoryDeletionStrategy;
-use App\Features\CategoryTree as CategoryTreeFeature;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\Settings\DeleteCategoryRequest;
 use App\Http\Requests\Settings\StoreCategoryRequest;
@@ -16,7 +15,6 @@ use Illuminate\Http\RedirectResponse;
 use Illuminate\Validation\ValidationException;
 use Inertia\Inertia;
 use Inertia\Response;
-use Laravel\Pennant\Feature;
 
 class CategoryController extends Controller
 {
@@ -36,7 +34,6 @@ class CategoryController extends Controller
 
         return Inertia::render('settings/categories', [
             'categories' => $categories,
-            'categoryTreeEnabled' => Feature::for(auth()->user())->active(CategoryTreeFeature::class),
         ]);
     }
 

resources/js/components/categories/parent-category-field.tsx

@@ -5,7 +5,6 @@ import { getDescendantIds } from '@/lib/category-tree';
 import { type Category } from '@/types/category';
 import { UUID } from '@/types/uuid';
 import { __ } from '@/utils/i18n';
-import { usePage } from '@inertiajs/react';
 import { useMemo } from 'react';
 
 interface ParentCategoryFieldProps {
@@ -24,10 +23,6 @@ export function ParentCategoryField({
     excludeId,
     error,
 }: ParentCategoryFieldProps) {
-    const enabled =
-        usePage<{ categoryTreeEnabled?: boolean }>().props
-            .categoryTreeEnabled ?? false;
-
     const byId = useMemo(
         () => new Map(categories.map((c) => [c.id, c])),
         [categories],
@@ -59,10 +54,6 @@ export function ParentCategoryField({
         );
     }, [categories, excludeId, byId]);
 
-    if (!enabled) {
-        return null;
-    }
-
     return (
         <div className="space-y-2">
             <Label htmlFor="parent_id">{__('Parent category')}</Label>