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/GotenbergPdfDriver.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace App\Support\Pdf;
+
+use Gotenberg\Gotenberg;
+use Gotenberg\Stream;
+
+class GotenbergPdfDriver
+{
+    public function loadView(string $viewname): GotenbergPdfResponse
+    {
+        $papersize = explode(' ', config('pdf.connections.gotenberg.papersize'));
+        if (count($papersize) != 2) {
+            throw new \InvalidArgumentException('Invalid Gotenberg Papersize specified');
+        }
+
+        $host = config('pdf.connections.gotenberg.host');
+        $request = Gotenberg::chromium($host)
+            ->pdf()
+            ->margins(0, 0, 0, 0)
+            ->paperSize($papersize[0], $papersize[1])
+            ->html(
+                Stream::string(
+                    'document.html',
+                    view($viewname)->render(),
+                )
+            );
+        $result = Gotenberg::send($request);
+
+        return new GotenbergPdfResponse($result);
+    }
+}