Server-side sorting for execution search results

Sorting now applies to the entire result set via ClickHouse ORDER BY
instead of only sorting the current page client-side. Default sort
order is timestamp descending. Supported sort columns: startTime,
status, agentId, routeId, correlationId, durationMs.

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/controller/SearchController.java

@@ -47,7 +47,9 @@ public class SearchController {
             @RequestParam(required = false) String agentId,
             @RequestParam(required = false) String processorType,
             @RequestParam(defaultValue = "0") int offset,
-            @RequestParam(defaultValue = "50") int limit) {
+            @RequestParam(defaultValue = "50") int limit,
+            @RequestParam(required = false) String sortField,
+            @RequestParam(required = false) String sortDir) {
 
         SearchRequest request = new SearchRequest(
                 status, timeFrom, timeTo,
@@ -55,7 +57,8 @@ public class SearchController {
                 correlationId,
                 text, null, null, null,
                 routeId, agentId, processorType,
-                offset, limit
+                offset, limit,
+                sortField, sortDir
         );
 
         return ResponseEntity.ok(searchService.search(request));