refactor: rename group/groupName to application/applicationName

The execution-related "group" concept actually represents the
application name. Rename all Java fields, API parameters, and frontend
types from groupName→applicationName and group→application for clarity.

- Java records: ExecutionSummary, ExecutionDetail, ExecutionDocument,
  ExecutionRecord, ProcessorRecord
- API params: SearchRequest.group→application, SearchController
  @RequestParam group→application
- Services: IngestionService, DetailService, SearchIndexer, StatsStore
- Frontend: schema.d.ts, Dashboard, ExchangeDetail, RouteDetail,
  executions query hooks

Database column names (group_name) and OpenSearch field names are
unchanged — only the API-facing Java/TS field names are renamed.

RBAC group references (groups table, GroupRepository, GroupsTab) are
a separate domain concept and are NOT affected by this change.

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

ui/src/pages/Routes/RouteDetail.tsx

@@ -51,7 +51,7 @@ export default function RouteDetail() {
     timeFrom,
     timeTo,
     routeId: routeId || undefined,
-    group: appId || undefined,
+    application: appId || undefined,
     offset: 0,
     limit: 50,
   });
@@ -59,7 +59,7 @@ export default function RouteDetail() {
     timeFrom,
     timeTo,
     routeId: routeId || undefined,
-    group: appId || undefined,
+    application: appId || undefined,
     status: 'FAILED',
     offset: 0,
     limit: 200,