Add connect-timeout to Matrix webhook calls (#77)

NotificationHelper::fire() set CURLOPT_TIMEOUT (10s total) but no
CURLOPT_CONNECTTIMEOUT, so a slow-but-not-hung hookshot endpoint could
add up to the full 10s per fire() call — and a single request can call
fire() more than once sequentially (e.g. add_comment.php firing
mention + comment + watcher notifications back to back), stacking into
tens of seconds of added latency on the user-facing response.

Added a 3s CURLOPT_CONNECTTIMEOUT so a slow-to-connect endpoint fails
fast without needing the full request to time out. Verified the
webhook still fires correctly end-to-end against a real local HTTP
server after the change.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Lhz7pGMaoTfL5sdYS5XiKv

helpers/NotificationHelper.php

@@ -20,6 +20,12 @@ class NotificationHelper
         curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload));
         curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
         curl_setopt($ch, CURLOPT_TIMEOUT, 10);
+        // A slow-but-not-fully-hung hookshot endpoint could otherwise add up
+        // to the full CURLOPT_TIMEOUT per fire() call, and a single request
+        // can call fire() (via notifyWatchers/sendCommentNotification/etc.)
+        // more than once sequentially — capping just the connect phase keeps
+        // that from stacking into tens of seconds of added latency.
+        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 3);
 
         $response  = curl_exec($ch);
         $httpCode  = curl_getinfo($ch, CURLINFO_HTTP_CODE);