Replace stub ILmxProxyClient with production proto-generated gRPC client
(RealLmxProxyClient) that connects to LmxProxy servers with x-api-key
metadata header authentication. Includes pre-generated proto stubs for
ARM64 Docker compatibility, updated adapter with proper quality mapping
(Good/Uncertain/Bad), subscription via server-streaming RPC, and 20 unit
tests covering all operations. Updated Component-DataConnectionLayer.md
to reflect the actual implementation.
e837eae2cc