Fix command palette: agent ID propagation, result selection, and scope tabs

- Propagate authenticated agent identity through write buffers via
  TaggedExecution/TaggedDiagram wrappers so ClickHouse rows get real
  agent IDs instead of empty strings
- Add execution_id to text search LIKE clause so selecting an execution
  by ID in the palette actually finds it
- Clear status filter to all three statuses on palette selection so the
  chosen execution/agent isn't filtered out
- Add disabled Routes and Exchanges scope tabs with "coming soon" state

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/components/command-palette/CommandPalette.tsx

@@ -22,12 +22,14 @@ export function CommandPalette() {
     (result: PaletteResult) => {
       if (result.type === 'execution') {
         const exec = result.data as ExecutionSummary;
+        execSearch.setStatus(['COMPLETED', 'FAILED', 'RUNNING']);
         execSearch.setText(exec.executionId);
         execSearch.setRouteId('');
         execSearch.setAgentId('');
         execSearch.setProcessorType('');
       } else if (result.type === 'agent') {
         const agent = result.data as AgentInstance;
+        execSearch.setStatus(['COMPLETED', 'FAILED', 'RUNNING']);
         execSearch.setAgentId(agent.agentId);
         execSearch.setText('');
         execSearch.setRouteId('');