Fix ticket page 500 from unbounded audit timeline (#112)

A ticket updated by hwmonDaemon had ~52k audit rows; getTicketTimeline()
loaded all of them and exhausted PHP's 128MB memory limit, so the ticket
page returned 500. Not related to the MCP server.

- getTicketTimeline() takes a limit (newest first). The ticket page shows
  the latest 500 events with a note when older ones are omitted; the JSON
  export caps at 5000.
- create_ticket_api.php: the description is refreshed on every run, and
  that alone wrote a reason-only audit row every few minutes per open
  ticket. Audit only real title/priority changes.
- create_ticket_api.php: after creating a brand-new ticket the dedup retry
  loop fell through into a second iteration on a closed connection,
  appending a 500 error body after the success response. Exit instead.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MGDKHiU5RJdo3dqQUDow3X

create_ticket_api.php

@@ -328,10 +328,17 @@ for ($dedupAttempt = 1; $dedupAttempt <= $maxDedupAttempts; $dedupAttempt++) {
                     $commentStmt->close();
                 }
 
-                $auditLog->log($userId, 'update', 'ticket', $existingId, array_merge(
-                    array_diff_key($changes, ['description_refreshed' => true]),
-                    ['reason' => 'auto-updated by hwmonDaemon (condition worsened)']
-                ));
+                // Audit only real title/priority changes. The description is
+                // refreshed on every run, and logging that alone wrote a
+                // reason-only row every few minutes per open ticket — 50k+ rows
+                // on one ticket, which broke its page (tinker_tickets#112).
+                $auditedChanges = array_diff_key($changes, ['description_refreshed' => true]);
+                if (!empty($auditedChanges)) {
+                    $auditLog->log($userId, 'update', 'ticket', $existingId, array_merge(
+                        $auditedChanges,
+                        ['reason' => 'auto-updated by hwmonDaemon (condition worsened)']
+                    ));
+                }
 
                 // Only notify on priority escalation — title-only updates (e.g. rising
                 // Power_On_Hours counter) should not generate a Matrix ping every hour.
@@ -581,4 +588,8 @@ for ($dedupAttempt = 1; $dedupAttempt <= $maxDedupAttempts; $dedupAttempt++) {
         http_response_code(500);
         echo json_encode(['success' => false, 'error' => 'Internal server error']);
     }
+    // Done — only the deadlock `continue` above may run the loop again.
+    // Falling through re-entered it on a closed connection, appending a
+    // 500 error body after the success response for every new ticket.
+    exit;
 }