refactor: reorganise Service/ into Provider/ and Renderer/ sub-namespaces

Move all provider-related classes, enums, interface and trait into
App\Service\Provider; move SvgRenderer into App\Service\Renderer.
ContributionAggregator stays at the Service root as the orchestrator.
Test namespaces and use statements updated to match.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/Unit/Service/Provider/ProviderStatusTest.php

@@ -0,0 +1,64 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Tests\Unit\Service\Provider;
+
+use App\Service\Provider\ProviderErrorCode;
+use App\Service\Provider\ProviderStatus;
+use App\Service\Provider\ProviderStatusType;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(ProviderStatus::class)]
+final class ProviderStatusTest extends TestCase
+{
+    #[Test]
+    public function it_serializes_ok_status(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Ok);
+
+        $this->assertSame(['status' => 'ok'], $status->toArray());
+    }
+
+    #[Test]
+    public function it_serializes_not_configured_status(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::NotConfigured);
+
+        $this->assertSame(['status' => 'not_configured'], $status->toArray());
+    }
+
+    #[Test]
+    public function it_serializes_error_status_with_code_and_message(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Error, ProviderErrorCode::AuthFailed, 'Token expired');
+
+        $this->assertSame([
+            'status'  => 'error',
+            'error'   => 'auth_failed',
+            'message' => 'Token expired',
+        ], $status->toArray());
+    }
+
+    #[Test]
+    public function it_omits_null_error_fields_from_array(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Ok);
+
+        $array = $status->toArray();
+
+        $this->assertArrayNotHasKey('error', $array);
+        $this->assertArrayNotHasKey('message', $array);
+    }
+
+    #[Test]
+    public function it_exposes_typed_status_property(): void
+    {
+        $status = new ProviderStatus('github', ProviderStatusType::Error, ProviderErrorCode::Unknown, 'msg');
+
+        $this->assertSame(ProviderStatusType::Error, $status->status);
+        $this->assertSame(ProviderErrorCode::Unknown, $status->error);
+    }
+}