Add super-admin Administration section and restructure global vs company settings

- Add Administration sidebar section (super-admin only) with Companies, Users, and Global Settings pages
- Add super-admin middleware, controllers, and API routes under /api/v1/super-admin/
- Allow super-admins to manage all companies and users across tenants
- Add user impersonation with short-lived tokens, audit logging, and UI banner
- Move system-level settings (Mail, PDF, Backup, Update, File Disk) from per-company to Administration > Global Settings
- Convert save_pdf_to_disk from CompanySetting to global Setting
- Add per-company mail configuration overrides (optional, falls back to global)
- Add CompanyMailConfigService to apply company mail config before sending emails

app/Http/Controllers/V1/SuperAdmin/CompaniesController.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace App\Http\Controllers\V1\SuperAdmin;
+
+use App\Http\Controllers\Controller;
+use App\Http\Requests\AdminCompanyUpdateRequest;
+use App\Http\Resources\CompanyResource;
+use App\Models\Company;
+use Illuminate\Http\Request;
+
+class CompaniesController extends Controller
+{
+    public function index(Request $request)
+    {
+        $companies = Company::query()
+            ->with(['owner', 'address'])
+            ->when($request->has('search'), function ($query) use ($request) {
+                $query->where('name', 'like', '%'.$request->search.'%');
+            })
+            ->when($request->has('orderByField') && $request->has('orderBy'), function ($query) use ($request) {
+                $query->orderBy($request->orderByField, $request->orderBy);
+            }, function ($query) {
+                $query->orderBy('name', 'asc');
+            })
+            ->paginate($request->input('limit', 10));
+
+        return CompanyResource::collection($companies);
+    }
+
+    public function show(Company $company)
+    {
+        $company->load(['owner', 'address']);
+
+        return new CompanyResource($company);
+    }
+
+    public function update(AdminCompanyUpdateRequest $request, Company $company)
+    {
+        $company->update([
+            'name' => $request->name,
+            'vat_id' => $request->vat_id,
+            'tax_id' => $request->tax_id,
+            'owner_id' => $request->owner_id,
+        ]);
+
+        if ($request->has('address')) {
+            $company->address()->updateOrCreate(
+                ['company_id' => $company->id],
+                $request->address,
+            );
+        }
+
+        $company->load(['owner', 'address']);
+
+        return new CompanyResource($company);
+    }
+}