feat(phase-11): CF11-006 Execution History Panel UI

- ExecutionHistoryPanel React component registered in sidebar (order 8.8)
- ExecutionList + ExecutionItem: scrollable list with status dots, duration, trigger type
- ExecutionDetail: summary, error display, trigger data, node steps
- NodeStepList + NodeStepItem: expandable rows with input/output JSON
- ExecutionFilters: status dropdown filter with clear button
- useExecutionHistory hook: IPC-based data fetching with filter support
- useExecutionDetail hook: single execution fetch with steps
- All styles use design tokens (no hardcoded colors)
- Unit tests: formatDuration, formatRelativeTime, buildExecutionQuery (Jasmine)
- CF11-007 canvas overlay integration point: onPinToCanvas prop stub

IPC channels expected from backend:
  execution-history:list (ExecutionQuery) -> WorkflowExecution[]
  execution-history:get (id) -> ExecutionWithSteps

packages/noodl-editor/tests/cloud/index.ts

@@ -1 +1,2 @@
 export * from './cloudformation';
+import './ExecutionHistoryPanel.test';