deprecate(lmxproxy): move all LmxProxy code, tests, and docs to deprecated/

LmxProxy is no longer needed. Moved the entire lmxproxy/ workspace, DCL
adapter files, and related docs to deprecated/. Removed LmxProxy registration
from DataConnectionFactory, project reference from DCL, protocol option from
UI, and cleaned up all requirement docs.

CLAUDE.md

@@ -7,8 +7,7 @@ This project contains design documentation for a distributed SCADA system built
 - `README.md` — Master index with component table and architecture diagrams.
 - `docs/requirements/HighLevelReqs.md` — Complete high-level requirements covering all functional areas.
 - `docs/requirements/Component-*.md` — Individual component design documents (one per component).
-- `docs/requirements/lmxproxy_protocol.md` — LmxProxy gRPC protocol specification.
+- `docs/test_infra/test_infra.md` — Master test infrastructure doc (OPC UA, LDAP, MS SQL, SMTP, REST API, Traefik).
-- `docs/test_infra/test_infra.md` — Master test infrastructure doc (OPC UA, LDAP, MS SQL, SMTP, REST API, LmxFakeProxy, Traefik).
 - `docs/plans/` — Design decision documents from refinement sessions.
 - `AkkaDotNet/` — Akka.NET reference documentation and best practices notes.
 - `infra/` — Docker Compose and config files for local test services.
@@ -160,5 +159,5 @@ This project contains design documentation for a distributed SCADA system built
 - **Test user**: `--username multi-role --password password` — has Admin, Design, and Deployment roles. The `admin` user only has the Admin role and cannot create templates, data connections, or deploy.
 - **Config file**: `~/.scadalink/config.json` — stores `managementUrl` and default format. See `docker/README.md` for a ready-to-use test config.
 - **Rebuild cluster**: `bash docker/deploy.sh` — builds the `scadalink:latest` image and recreates all containers. Run this after code changes to ManagementActor, Host, or any server-side component.
-- **Infrastructure services**: `cd infra && docker compose up -d` — starts LDAP, MS SQL, OPC UA, SMTP, REST API, and LmxFakeProxy. These are separate from the cluster containers in `docker/`.
+- **Infrastructure services**: `cd infra && docker compose up -d` — starts LDAP, MS SQL, OPC UA, SMTP, and REST API. These are separate from the cluster containers in `docker/`.
 - **All test LDAP passwords**: `password` (see `infra/glauth/config.toml` for users and groups).

ScadaLink.slnx

@@ -20,9 +20,6 @@
     <Project Path="src/ScadaLink.ManagementService/ScadaLink.ManagementService.csproj" />
     <Project Path="src/ScadaLink.CLI/ScadaLink.CLI.csproj" />
   </Folder>
-  <Folder Name="/external/">
-    <Project Path="lmxproxy/src/ZB.MOM.WW.LmxProxy.Client/ZB.MOM.WW.LmxProxy.Client.csproj" />
-  </Folder>
   <Folder Name="/tests/">
     <Project Path="tests/ScadaLink.Commons.Tests/ScadaLink.Commons.Tests.csproj" />
     <Project Path="tests/ScadaLink.Host.Tests/ScadaLink.Host.Tests.csproj" />