Fix upstream delta text parsing

response_cache.py

@@ -258,6 +258,7 @@ class InFlightRegistry:
             future = self._futures.pop(key, None)
         if future is not None and not future.done():
             future.set_exception(exc)
+            future.add_done_callback(lambda f: f.exception())
 
 
 class ResponseCacheService:

upstream.py

@@ -127,8 +127,15 @@ async def iter_upstream_events(payload: dict) -> AsyncIterator[tuple[str, dict]]
                         skipped_lines += 1
                         continue
                     if t == "delta" and "text" in obj and "index" not in obj:
-                        skipped_lines += 1
-                        continue
+                        obj = {
+                            "type": "content_block_delta",
+                            "index": 0,
+                            "delta": {"type": "text_delta", "text": obj.get("text", "")},
+                        }
+                        t = "content_block_delta"
+                    if t == "error":
+                        yield ("error", {"status_code": 502, "body": obj.get("message") or json.dumps(obj, ensure_ascii=False)})
+                        return
                     event_counts[t] = event_counts.get(t, 0) + 1
                     yield (t, obj)