feat: store raw processor tree JSON and add error categorization fields

Fixes iteration overlay corruption caused by flat storage collapsing
duplicate processorIds across loop iterations.

Server:
- Store raw processor tree as processors_json JSONB on executions table
- Detail endpoint serves from processors_json (faithful tree), falls back
  to flat record reconstruction for older executions
- V10 migration: processors_json, error categorization (errorType,
  errorCategory, rootCauseType, rootCauseMessage), OTel (traceId, spanId),
  circuit breaker (circuitBreakerState, fallbackTriggered), drops
  erroneous splitDepth/loopDepth columns
- Add all new fields through full ingestion/storage/API chain

UI:
- Fix overlay wrapper filtering: check wrapper type before status filter
- Add new fields to schema.d.ts

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

ui/src/components/ExecutionDiagram/useExecutionOverlay.ts

@@ -29,10 +29,10 @@ function buildOverlay(
   parentId?: string,
 ): void {
   for (const proc of processors) {
-    if (!proc.processorId || !proc.status) continue;
-    if (proc.status !== 'COMPLETED' && proc.status !== 'FAILED') continue;
+    if (!proc.processorId) continue;
 
-    // Iteration wrapper: filter by selected iteration, skip the wrapper itself
+    // Iteration wrapper: filter by selected iteration, skip the wrapper itself.
+    // Must be checked before the status filter — wrappers may not have a status.
     if (ITERATION_WRAPPER_TYPES.has(proc.processorType)) {
       if (parentId && iterationState.has(parentId)) {
         const info = iterationState.get(parentId)!;
@@ -48,7 +48,9 @@ function buildOverlay(
       continue;
     }
 
-    // Regular processor: add to overlay
+    // Regular processor: only include completed/failed nodes
+    if (!proc.status || (proc.status !== 'COMPLETED' && proc.status !== 'FAILED')) continue;
+
     const subRouteFailed =
       proc.status === 'FAILED' &&
       (proc.processorType?.includes('DIRECT') || proc.processorType?.includes('SEDA'));