Modernize: remove unused deps, replace qirolab/laravel-themer with custom ThemeService, drop doctrine/dbal

- Remove whichbrowser/parser, mockery/mockery, fruitcake/laravel-debugbar,
  itsgoingd/clockwork (all unused)
- Replace qirolab/laravel-themer (dev-master) with custom App\Services\ThemeService
  and App\Providers\ThemeServiceProvider
- Drop doctrine/dbal: rewrite all ->change() calls in 8 migrations to raw
  DB::statement('ALTER TABLE ... MODIFY ...') SQL
- RenameColumn() kept intact (works without dbal in Laravel 13)
- Fix 2026_04_04 migration: inverted column-exists logic corrected
- Clear bootstrap cache to remove stale references to removed packages

app/Providers/ThemeServiceProvider.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Providers;
+
+use App\Services\ThemeService;
+use Illuminate\Support\ServiceProvider;
+
+class ThemeServiceProvider extends ServiceProvider
+{
+    public function register(): void
+    {
+        $this->app->singleton(ThemeService::class, fn () => new ThemeService);
+    }
+
+    public function boot(): void
+    {
+        if (config('theme.active')) {
+            app(ThemeService::class)->set(
+                config('theme.active'),
+                config('theme.parent'),
+            );
+        }
+    }
+}