Stream Whisper uploads with curl so large audio does not OOM.

tests/fixtures/whisper-sse-stub.php

@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * Tiny Whisper-compatible stub for curl transport tests.
+ * Speaks OpenAI-style /v1/audio/transcriptions SSE.
+ */
+$uri = parse_url($_SERVER['REQUEST_URI'] ?? '/', PHP_URL_PATH) ?: '/';
+
+if ($uri !== '/v1/audio/transcriptions' && $uri !== '/audio/transcriptions') {
+    http_response_code(404);
+    header('Content-Type: application/json');
+    echo '{"error":"not found"}';
+
+    return;
+}
+
+// Drain the multipart body without keeping it in a string longer than needed.
+$stdin = fopen('php://input', 'rb');
+if (is_resource($stdin)) {
+    while (! feof($stdin)) {
+        fread($stdin, 8192);
+    }
+    fclose($stdin);
+}
+
+header('Content-Type: text/event-stream');
+header('Cache-Control: no-cache');
+
+echo "data: {\"type\":\"transcript.text.delta\",\"delta\":\"Hello \",\"end\":10}\n\n";
+echo "data: {\"type\":\"transcript.text.delta\",\"delta\":\"from whisper.\",\"end\":30}\n\n";
+echo "data: {\"type\":\"transcript.text.done\",\"text\":\"Hello from whisper.\",\"end\":40}\n\n";
+flush();