refactor(services): split driver infrastructure out of Services into Support

Services/Integrations/ExchangeRate/ and Services/Pdf/ were both mostly Support-shaped: interfaces, abstract classes, static factories, concrete adapter drivers, DTOs, and exceptions — infrastructure that doesn't carry business logic. They only each had one real DI-injected service mixed in.

This commit applies the same Services=DI-business-logic / Support=stateless-plumbing rule we've been using throughout the reorg:

**Moved to Support/Integrations/ExchangeRate/** (7 files): ExchangeRateDriver (abstract), ExchangeRateDriverFactory (static), ExchangeRateException, and the four concrete drivers (CurrencyConverter, CurrencyFreak, CurrencyLayer, OpenExchangeRate). These are HTTP adapters over third-party currency APIs — same shape as the Hashids library wrapper classes already in Support.

**Moved to Support/Pdf/** (6 files, merging with existing Pdf utilities): PdfDriver (interface), PdfDriverFactory (static), PdfService (static facade), GotenbergPdfDriver, GotenbergPdfResponse (DTO), ResponseStream (interface). The Support/Pdf/ dir now contains the full PDF rendering subsystem — drivers + sanitizer + template/image utilities.

**Promoted to Services/ root** (the real DI services): ExchangeRateProviderService (CRUD for ExchangeRateProvider model) and FontService (font package install/download orchestration). Both are proper DI services — instance methods, model writes, HTTP side effects.

Services/Integrations/ and Services/Pdf/ are now empty and deleted. Services/ holds only DI-injected classes; Support/ holds all the plumbing.

17 files renamed (git detects 90-99% similarity), 4 consumer files updated (DriverRegistryProvider, PdfServiceProvider, ExchangeRateProviderController, FontController, GeneratesPdfTrait, test). 350 tests pass, Pint clean.

app/Support/Pdf/GotenbergPdfResponse.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Support\Pdf;
+
+use Illuminate\Http\Response;
+use Psr\Http\Message\ResponseInterface;
+
+class GotenbergPdfResponse
+{
+    protected ResponseInterface $response;
+
+    public function __construct($stream)
+    {
+        $this->response = $stream;
+    }
+
+    public function stream(string $filename = 'document.pdf'): Response
+    {
+        $output = $this->response->getBody();
+
+        return new Response($output, 200, [
+            'Content-Type' => 'application/pdf',
+            'Content-Disposition' => 'inline; filename="'.$filename.'"',
+        ]);
+    }
+
+    public function output(): string
+    {
+        return $this->response->getBody()->getContents();
+    }
+}