fix: compute hasTraceData from processor records in chunk accumulator

The chunked ingestion path hardcoded hasTraceData=false because the
execution envelope doesn't carry processor bodies. But the processor
records DO have inputBody/outputBody — we just need to check them.

Track hasTraceData across chunks in PendingExchange and pass it to
MergedExecution when the final chunk arrives or on stale sweep.

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

cameleer3-server-core/src/main/java/com/cameleer3/server/core/ingestion/ChunkAccumulator.java

@@ -50,6 +50,7 @@ public class ChunkAccumulator {
      */
     public void onChunk(ExecutionChunk chunk) {
         // 1. Push processor records immediately (append-only)
+        boolean chunkHasTrace = false;
         if (chunk.getProcessors() != null && !chunk.getProcessors().isEmpty()) {
             processorSink.accept(new ProcessorBatch(
                     DEFAULT_TENANT,
@@ -58,6 +59,8 @@ public class ChunkAccumulator {
                     chunk.getApplicationId(),
                     chunk.getStartTime(),
                     chunk.getProcessors()));
+            chunkHasTrace = chunk.getProcessors().stream()
+                    .anyMatch(p -> isNonEmpty(p.getInputBody()) || isNonEmpty(p.getOutputBody()));
         }
 
         // 2. Buffer/merge the exchange envelope
@@ -67,17 +70,24 @@ public class ChunkAccumulator {
             ExecutionChunk merged = existing != null
                     ? mergeEnvelopes(existing.envelope(), chunk)
                     : chunk;
-            executionSink.accept(toMergedExecution(merged));
+            boolean hasTrace = chunkHasTrace || (existing != null && existing.hasTraceData());
+            executionSink.accept(toMergedExecution(merged, hasTrace));
         } else {
             // Buffer the envelope for later merging
+            boolean trace = chunkHasTrace;
             pending.merge(chunk.getExchangeId(),
-                    new PendingExchange(chunk, Instant.now()),
+                    new PendingExchange(chunk, Instant.now(), trace),
                     (old, incoming) -> new PendingExchange(
                             mergeEnvelopes(old.envelope(), incoming.envelope()),
-                            old.receivedAt()));
+                            old.receivedAt(),
+                            old.hasTraceData() || incoming.hasTraceData()));
         }
     }
 
+    private static boolean isNonEmpty(String s) {
+        return s != null && !s.isEmpty();
+    }
+
     /**
      * Flush exchanges that have been pending longer than the stale threshold.
      * Called periodically by a scheduled task.
@@ -90,7 +100,7 @@ public class ChunkAccumulator {
                 if (removed != null) {
                     log.info("Flushing stale exchange {} (pending since {})",
                             exchangeId, removed.receivedAt());
-                    executionSink.accept(toMergedExecution(removed.envelope()));
+                    executionSink.accept(toMergedExecution(removed.envelope(), removed.hasTraceData()));
                 }
             }
         });
@@ -142,7 +152,7 @@ public class ChunkAccumulator {
 
     // ---- Conversion to MergedExecution ----
 
-    private MergedExecution toMergedExecution(ExecutionChunk envelope) {
+    private MergedExecution toMergedExecution(ExecutionChunk envelope, boolean hasTraceData) {
         String diagramHash = "";
         try {
             diagramHash = diagramStore
@@ -179,7 +189,7 @@ public class ChunkAccumulator {
                 serializeAttributes(envelope.getAttributes()),
                 envelope.getTraceId(),
                 envelope.getSpanId(),
-                false,  // hasTraceData — not tracked at envelope level
+                hasTraceData,
                 envelope.getReplayExchangeId() != null,  // isReplay
                 envelope.getOriginalExchangeId(),
                 envelope.getReplayExchangeId()
@@ -215,5 +225,5 @@ public class ChunkAccumulator {
     /**
      * Envelope buffered while waiting for the final chunk.
      */
-    private record PendingExchange(ExecutionChunk envelope, Instant receivedAt) {}
+    private record PendingExchange(ExecutionChunk envelope, Instant receivedAt, boolean hasTraceData) {}
 }