- Remove the 2-second polling wait for gossipsub mesh formation in `Publish`
to eliminate unnecessary latency, relying on `FloodPublish` for delivery.
- Introduce a per-invocation publish budget (1000 messages) to prevent
potential flooding of the shared gossipsub router by WASM functions.
- Add regression tests to ensure `Publish` remains non-blocking and that
the publish budget is strictly enforced.