fix(x): stop chunked video upload from exhausting memory

The APPEND loop sent each 1MB segment without releasing it: the chunk plus
its multipart copies and the Guzzle/retry object graph were kept alive by
reference cycles the GC doesn't reclaim mid-loop, so memory grew ~4MB per
segment. A 49MB video peaked at ~242MB locally and crossed the 512MB limit
in production. Freeing the segment and forcing cycle collection each
iteration keeps memory flat (~50MB regardless of video size).

Also harden socialHttp()'s retry predicate: it read $exception->response
directly, which fatals on exceptions without a response (e.g. a
ConnectionException during a long upload), masking the real error.

app/Services/Social/Concerns/HasSocialHttpClient.php

@@ -32,7 +32,7 @@ protected function socialHttp(): PendingRequest
         return Http::retry(
             times: 3,
             sleepMilliseconds: 5000,
-            when: fn ($exception, $request) => $exception->response?->status() === 429,
+            when: fn ($exception, $request) => ($exception->response ?? null)?->status() === 429,
             throw: false,
         )->timeout(120);
     }

app/Services/Social/XPublisher.php

@@ -236,6 +236,12 @@ private function chunkedUpload(string $tempFile, int $totalBytes, string $mimeTy
                 }
 
                 $index++;
+
+                // The HTTP client/retry wrapper keeps each segment's body alive
+                // through reference cycles, so without forcing collection a large
+                // video accumulates its full size in memory and exhausts the limit.
+                unset($chunk, $appendResponse);
+                gc_collect_cycles();
             }
         } finally {
             fclose($handle);

tests/Feature/Services/Social/XPublisherTest.php

@@ -304,3 +304,52 @@
     Http::assertSent(fn ($request) => str_contains($request->url(), '/finalize'));
     Http::assertSent(fn ($request) => str_contains($request->url(), '/2/tweets'));
 });
+
+test('x publisher uploads a large video in sequential 1MB segments', function () {
+    $this->post->update([
+        'media' => [
+            [
+                'id' => 'test-media-video',
+                'path' => 'media/2026-01/big-video.mp4',
+                'url' => 'https://example.com/media/2026-01/big-video.mp4',
+                'mime_type' => 'video/mp4',
+                'original_filename' => 'big-video.mp4',
+            ],
+        ],
+    ]);
+
+    $appendCount = 0;
+
+    Http::fake(function ($request) use (&$appendCount) {
+        $url = $request->url();
+
+        if (str_contains($url, '/2/media/upload/initialize')) {
+            return Http::response(['data' => ['id' => 'media_id_999']], 200);
+        }
+
+        if (str_contains($url, '/append')) {
+            $appendCount++;
+
+            return Http::response(null, 204);
+        }
+
+        if (str_contains($url, '/finalize')) {
+            return Http::response(['data' => ['id' => 'media_id_999']], 200);
+        }
+
+        if (str_contains($url, '/2/media/')) {
+            return Http::response(['processing_info' => ['state' => 'succeeded']], 200);
+        }
+
+        if (str_contains($url, '/2/tweets')) {
+            return Http::response(['data' => ['id' => '9876543210987654321', 'text' => 'Hello from X!']], 200);
+        }
+
+        // ~2.5MB download -> at least three 1MB segments.
+        return Http::response(str_repeat('x', (int) (2.5 * 1024 * 1024)), 200);
+    });
+
+    $this->publisher->publish($this->postPlatform);
+
+    expect($appendCount)->toBeGreaterThan(1);
+});