refactor: add declare(strict_types=1) to remaining PHP files

Add strict_types declaration to 9 scaffold/config files that were
missed in the earlier dx-audit pass (bcb40d4). All non-blade PHP
files in the repository now enforce strict typing per CLAUDE.md
conventions.

Files: bootstrap/app.php, bootstrap/providers.php, config/core.php,
database/seeders/DatabaseSeeder.php, public/index.php, routes/*.php,
app/Providers/AppServiceProvider.php

Fixes #5

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/Providers/AppServiceProvider.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace App\Providers;
 
 use Illuminate\Support\ServiceProvider;

bootstrap/app.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Illuminate\Foundation\Application;
 use Illuminate\Foundation\Configuration\Exceptions;
 use Illuminate\Foundation\Configuration\Middleware;

bootstrap/providers.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 return [
     App\Providers\AppServiceProvider::class,
 ];

config/core.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 return [
     /*
     |--------------------------------------------------------------------------

database/seeders/DatabaseSeeder.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace Database\Seeders;
 
 use Illuminate\Database\Seeder;

public/index.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Illuminate\Http\Request;
 
 define('LARAVEL_START', microtime(true));

routes/api.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Illuminate\Support\Facades\Route;
 
 // API routes are registered via Core modules

routes/console.php

@@ -1,3 +1,5 @@
 <?php
 
+declare(strict_types=1);
+
 // Console commands are registered via Core modules

routes/web.php

@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 use Illuminate\Support\Facades\Route;
 
 Route::get('/', function () {