fix(platform): expose run correlation in list

apps/api/src/services/runtime_correlation.py

@@ -101,6 +101,25 @@ def canonical_work_item_id(project_id: str, run_id: UUID) -> str:
     return f"platform-run:{project}:{run_id}"
 
 
+def correlation_readback_for_run(
+    project_id: str,
+    run_id: UUID,
+    trace_id: str | None,
+) -> dict[str, str | None]:
+    """Project stored trace truth plus its canonical run-bound work item."""
+
+    stored_trace_id = None if trace_id is None else str(trace_id)
+    return {
+        "trace_id": stored_trace_id,
+        "work_item_id": canonical_work_item_id(project_id, run_id),
+        "correlation_status": (
+            "canonical"
+            if is_canonical_traceparent(stored_trace_id or "", run_id=run_id)
+            else "legacy_or_invalid_trace"
+        ),
+    }
+
+
 def correlation_for_run(project_id: str, run_id: UUID) -> RuntimeCorrelation:
     """Build the canonical public-safe correlation projection for a run."""