Stop execution when server reports "Envoy XXX is too old and is not supported by Consul"

We're using AWS ECS architecture, and we noticed if a given service is using old versions of envoy proxy not accepted by the servers, the dataplane container keeps running indefinitely, conceptually this should be a terminating error, given there is no exit condition for this loop.

```log
2026-08-13T08:52:15.834Z+00:00 [warning] envoy.config(44) DeltaAggregatedResources gRPC config stream to consul-dataplane closed: 3, Envoy 1.33.6 is too old and is not supported by Consul
```

Search the codebase for handling of the Envoy configuration stream and the exact "too old and is not supported" error, then trace how dataplane process errors affect its lifecycle. Confirm the existing tests around stream or startup failures and add coverage showing that this terminating error causes the container to exit instead of retrying indefinitely.

Written by the indexing model from the issue text.