Describe the bug

A data update sent to a scope via POST /scopes/{scope_id}/data/update never reaches that scope's OPAL clients; every entry is dropped, whatever topic you send.

The endpoint rewrites each entry's topics to data:{topic} (scopes/api.py#L350) and publishes through ScopedServerSideTopicPublisher, which scope-prefixes only the channel (publisher.py#L206), not the payload. So the message is delivered on channel {scope_id}:data:{topic} (the client is subscribed there), but each entry's own topics stay data:{topic}. The scoped client filters entries with set(entry.topics).isdisjoint(self._data_topics) against its namespaced {scope_id}:data:{topic} (updater.py#L482), so the entry is skipped before any fetch. No topic value works: the server forces data:{topic} and the client only matches {scope_id}:data:{topic}. The global POST /data/config is not an alternative for scoped clients, since it publishes un-prefixed channels they are not subscribed to.

To Reproduce

docker/docker-compose-scopes-example.yml, with the client pointed at scope documents:

  opal_client:
    environment:
      - OPAL_SCOPE_ID=documents
      - OPAL_DATA_TOPICS=data      # subscribes to documents:data:data
      - OPAL_LOG_LEVEL=DEBUG

$ curl -s -X POST http://localhost:7002/scopes/documents/data/update \
    -H 'Content-Type: application/json' \
    --data-binary '{"entries":[{"url":"http://opal_server:7002/healthcheck","topics":["data"],"dst_path":"/scope_probe","save_method":"PUT"}],"reason":"repro"}'
$ curl -s http://localhost:8181/v1/data/scope_probe
{}

The channel matches (so it is delivered), the entry topics do not (so it is dropped):

opal_server | data_update_publisher | Publishing data update to topics: {'data:data'}, entries: [{'path': '/scope_probe', 'topics': ['data:data']}]
opal_server | opal_common.topics.publisher | Publishing to topics: ['documents:data:data']
opal_client | data.updater | Data entry ... topics=['data:data'] dst_path='/scope_probe' ... has no topics matching the data topics, skipping

opal_server.data.data_update_publisher  | INFO  | Publishing data update to topics: {'data:data'}, reason: repro, entries: [{'url': 'http://opal_server:7002/healthcheck', 'method': 'PUT', 'path': '/scope_probe', 'inline_data': False, 'topics': ['data:data']}]
opal_common.topics.publisher            | INFO  | Publishing to topics: ['documents:data:data']
opal_client.data.updater                | INFO  | Subscribing to topics: ['documents:data:data']
opal_client.data.updater                | DEBUG | Data entry url='http://opal_server:7002/healthcheck' config=None topics=['data:data'] dst_path='/scope_probe' save_method='PUT' data=None has no topics matching the data topics, skipping

Expected behavior

The update reaches the scope's clients. The entry-content topics should be scope-prefixed to {scope_id}:data:{topic}, same as the channel. Happy to open a PR.

OPAL version

master (76f898e); permitio/opal-server:latest tracks the same code.

Related: #779.