Clear search box when opening Autotask Link existing modal

Fixed issue where the search input retained previous search text when
reopening the Link existing modal. The search box now always starts
empty for a better user experience.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

containers/backupchecks/src/templates/main/run_checks.html

@@ -1134,6 +1134,7 @@ table.addEventListener('change', function (e) {
         btnAutotaskLink.addEventListener('click', function () {
           if (!currentRunId) { alert('Select a run first.'); return; }
           if (atlStatus) atlStatus.textContent = '';
+          if (atlSearch) atlSearch.value = '';
           renderAtlRows([]);
           // Show the existing Run Checks popup first, then switch to the Autotask popup.
           // This prevents the main popup from breaking due to stacked modal backdrops.

docs/changelog-claude.md

@@ -28,6 +28,7 @@ This file documents all changes made to this project via Claude Code.
     - If time entries exist: keeps current status unchanged (ticket remains open)
 
 ### Fixed
+- Autotask "Link existing" search box now clears when opening the modal instead of retaining previous search text
 - Autotask ticket resolution update now correctly preserves exact field values from GET response in PUT payload.
   The `issueType`, `subIssueType`, and `source` fields are copied with their exact values (including null)
   from the GET response, as required by Autotask API. Previously these fields were being skipped or modified.