v0.51.538 — Release SW (gateway approval cards work on the default legacy path)

Fixed

Approval-gated tools no longer hang forever on standard gateway deployments (#4549).

Gateway deployments that don't set HERMES_WEBUI_GATEWAY_USE_RUNS_API (the default, legacy /v1/chat/completions path) silently dropped approval.request / hermes.approval.request events in the SSE relay loop — the agent said "please approve in the UI" but the approval card never rendered and the run hung at "Thinking…" until timeout. #4495 fixed the runs-API path but left the legacy path untouched.

The legacy SSE loop now handles approval events (reusing _gateway_runs_approval_event and the polling-state mirror), and records the gateway run_id so the user's approve/deny choice relays back to the gateway and actually resumes the parked run.

Thanks @rodboev.