refactor(github): make GitHubProvider fetch non-blocking

startFetch() fires the GraphQL POST and returns the response without
reading it; resolveFetch() does the .toArray()/parse/log work that
used to happen inline right after the request.

src/Service/Provider/GitHubProvider.php

@@ -9,6 +9,7 @@ use IDCI\Bundle\GraphQLClientBundle\Client\GraphQLApiClientRegistryInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException;
 use Symfony\Contracts\HttpClient\HttpClientInterface;
+use Symfony\Contracts\HttpClient\ResponseInterface;
 
 /**
  * Fetches the last 365 days of contributions from the GitHub GraphQL API.
@@ -46,10 +47,7 @@ final class GitHubProvider implements ProviderInterface
         ])->getContent();
     }
 
-    /**
-     * @return array<string, int>  date (Y-m-d) => contribution count
-     */
-    public function fetch(): array
+    public function startFetch(): ResponseInterface
     {
         $this->logger->debug('GitHubProvider: fetching contributions', ['user' => $this->username]);
 
@@ -75,15 +73,24 @@ final class GitHubProvider implements ProviderInterface
 
         // GitHub's GraphQL API requires application/json — the bundle's built-in
         // transport sends form_params, so we use Symfony HttpClient here instead.
-        $response = $this->client->request('POST', self::GRAPHQL_URL, [
+        // request() doesn't block; the response is read in resolveFetch() so
+        // multiple providers' requests can be in flight at once.
+        return $this->client->request('POST', self::GRAPHQL_URL, [
             'headers' => [
                 'Authorization' => "Bearer {$this->token}",
                 'Content-Type'  => 'application/json',
             ],
             'json' => ['query' => $query],
         ]);
+    }
 
-        $data = $response->toArray();
+    /**
+     * @return array<string, int>  date (Y-m-d) => contribution count
+     */
+    public function resolveFetch(mixed $handle): array
+    {
+        /** @var ResponseInterface $handle */
+        $data = $handle->toArray();
 
         if (isset($data['errors'])) {
             throw new ServiceUnavailableHttpException(null, 'GitHub GraphQL error: ' . json_encode($data['errors']));