feat(roles): role CRUD screen (list + form name/description + view/edit/delete + bulk)

Per request:
- Migration: add nullable 'description' to the roles table.
- RoleManager Livewire component + view at /admin/roles:
  * Roles list table with per-row checkboxes for bulk selection (+ select-all)
    and a 'Delete selected' bulk action (protected roles skipped).
  * 'New role' opens a modal form with just Name + Description (and permission
    checkboxes to assign).
  * Per-row View / Edit / Delete buttons (View modal shows description,
    counts and assigned permissions).
- Admin role stays protected (no rename/delete/lose 'manage all').
- /admin/users links to the new Roles screen; the phase-1 permission matrix
  stays available via a 'Matrix view' link.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

database/migrations/2026_06_17_170000_add_description_to_roles_table.php

@@ -0,0 +1,30 @@
+<?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
+    {
+        $table = config('permission.table_names.roles', 'roles');
+
+        Schema::table($table, function (Blueprint $table) {
+            if (! Schema::hasColumn($table->getTable(), 'description')) {
+                $table->string('description')->nullable()->after('name');
+            }
+        });
+    }
+
+    public function down(): void
+    {
+        $table = config('permission.table_names.roles', 'roles');
+
+        Schema::table($table, function (Blueprint $table) {
+            if (Schema::hasColumn($table->getTable(), 'description')) {
+                $table->dropColumn('description');
+            }
+        });
+    }
+};