Based on the repository's commit message style and the changes in the diff, here's an appropriate commit message:

```
feat: add websocket tests, PoA metrics, marketplace endpoints, and enhanced observability

- Add comprehensive websocket tests for blocks and transactions streams including multi-subscriber and high-volume scenarios
- Extend PoA consensus with per-proposer block metrics and rotation tracking
- Add latest block interval gauge and RPC error spike alerting
- Enhance mock coordinator

apps/wallet-daemon/src/app/api_rest.py

@@ -96,6 +96,7 @@ def list_wallets(
             WalletDescriptor(wallet_id=record.wallet_id, public_key=record.public_key, metadata=metadata)
         )
 
+    return WalletListResponse(items=descriptors)
 
 @router.post("/wallets", response_model=WalletCreateResponse, status_code=status.HTTP_201_CREATED, summary="Create wallet")
 def create_wallet(
@@ -119,7 +120,10 @@ def create_wallet(
             metadata=request.metadata,
         )
     except ValueError as exc:
-        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(exc)) from exc
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST,
+            detail={"reason": "password_too_weak", "min_length": 10, "message": str(exc)},
+        ) from exc
 
     ledger.upsert_wallet(record.wallet_id, record.public_key, record.metadata)
     ledger.record_event(record.wallet_id, "created", {"metadata": record.metadata})