tim plugin, chat bot sync notifications, test fixes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

public/plugins/collab-buckets/backend.php

@@ -648,6 +648,17 @@ function collabSyncCards(PDO $db): array {
             $stats['pulled']++;
             if ($foreignAuthor) $unreadBuckets[$c['bucket_uid']] = true;
 
+            // Notify the card's author that we synced it (best-effort; bot
+            // chat message, rendered in orange on the author's side). Only
+            // fires for cards authored by someone else.
+            if ($foreignAuthor && !empty($c['author_username'])) {
+                $cardTitle = trim((string)($fields['title'] ?? '')) ?: '(untitled)';
+                collabRelayCall('/api/chat/bot', 'POST', [
+                    'recipient' => $c['author_username'],
+                    'body'      => $selfUser . ' synced: ' . $cardTitle,
+                ]);
+            }
+
             // Fetch missing attachments referenced in the body.
             $pulledBody = $fields['body'] ?? '';
             if ($pulledBody && preg_match_all('#uploads/([a-f0-9]+\.\w+)#', $pulledBody, $fm)) {