chore: organize solution into module folders (Core/Server/Drivers/Client/Tooling)

Group all 69 projects into category subfolders under src/ and tests/ so the
Rider Solution Explorer mirrors the module structure. Folders: Core, Server,
Drivers (with a nested Driver CLIs subfolder), Client, Tooling.

- Move every project folder on disk with git mv (history preserved as renames).
- Recompute relative paths in 57 .csproj files: cross-category ProjectReferences,
  the lib/ HintPath+None refs in Driver.Historian.Wonderware, and the external
  mxaccessgw refs in Driver.Galaxy and its test project.
- Rebuild ZB.MOM.WW.OtOpcUa.slnx with nested solution folders.
- Re-prefix project paths in functional scripts (e2e, compliance, smoke SQL,
  integration, install).

Build green (0 errors); unit tests pass. Docs left for a separate pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests/Docker/README.md

@@ -0,0 +1,103 @@
+# opc-plc Docker fixture
+
+[Microsoft Industrial IoT's opc-plc](https://github.com/Azure-Samples/iot-edge-opc-plc)
+— pinned Docker image that stands up an OPC UA server at
+`opc.tcp://localhost:50000` with step-up counters, random nodes, alarm
+simulation, and other canonical simulated shapes. Replaces the PowerShell
+launcher pattern used by the Modbus / S7 fixtures — Docker is the launcher
+here since opc-plc ships pre-containerized.
+
+| File | Purpose |
+|---|---|
+| [`docker-compose.yml`](docker-compose.yml) | Service definition for `otopcua-opc-plc` — image pin, port map, command flags. |
+| (this file) | How to run it. |
+
+## Install
+
+Docker Desktop (Windows) or the docker CLI + daemon (Linux/macOS). Per
+`CLAUDE.md` Phase 1 decision #134 the dev box already has Docker Desktop
+configured with the WSL 2 backend — nothing new to install.
+
+## Run
+
+From the repo root:
+
+```powershell
+docker compose -f tests\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests\Docker\docker-compose.yml up
+```
+
+Or from this folder:
+
+```powershell
+docker compose up
+```
+
+First run pulls the image (~250 MB). Startup takes ~5-10 seconds; the
+healthcheck in the compose file surfaces ready state in `docker ps`.
+
+To run detached (CI pattern):
+
+```powershell
+docker compose up -d
+```
+
+Stop with `docker compose down` (removes the container) or `docker compose stop`
+(keeps it for fast restart).
+
+## Endpoint
+
+- Default: `opc.tcp://localhost:50000`
+- Override by setting `OPCUA_SIM_ENDPOINT` before `dotnet test` — e.g. point
+  at a real OPC UA server in the lab, or at a different Docker host.
+
+## What opc-plc advertises
+
+Command flags in `docker-compose.yml` enable:
+
+- `--pn=50000` — OPC UA endpoint on port 50000
+- `--ut` — unsecured transport endpoint advertised (SecurityPolicy=None).
+  Secured policies are still on the endpoint list; `--ut` just adds an
+  unsecured option.
+- `--aa` — auto-accept client certs (opc-plc's cert trust store lives
+  inside the container + resets each spin-up, so without this the driver's
+  first contact would be rejected).
+- `--alm` — alarm simulation enabled; opc-plc publishes
+  `TripAlarmType`, `ExclusiveDeviationAlarmType`,
+  `NonExclusiveLevelAlarmType`, and `DialogConditionType` events.
+
+Not turned on (but available via compose-file tweaks):
+
+- `--daa` — disable anonymous auth; forces username or cert tokens. Flip
+  on when username-auth / cert-auth smoke tests land.
+- `--fn` / `--fr` / `--ft` — fast-node variants (100 / 1 000 / 10 000 Hz
+  update rates) for subscription-stress coverage. Not needed for smoke.
+- `--sn` / `--sr` — slow-node / special-shape coverage.
+
+## Run the integration tests
+
+In a separate shell, with the simulator running:
+
+```powershell
+cd C:\Users\dohertj2\Desktop\lmxopcua
+dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests
+```
+
+Tests auto-skip with a clear `SkipReason` when `localhost:50000` isn't
+reachable within 2 seconds (`OpcPlcFixture`).
+
+## Known limitations
+
+opc-plc uses the OPCFoundation.NetStandard stack internally — same as
+our driver. That means bugs common to the stack itself are **not** caught
+by this fixture; the follow-up to add `open62541/open62541` as a second
+independent-stack image (task tracked in #215's follow-ups) would close
+that.
+
+See [`docs/drivers/OpcUaClient-Test-Fixture.md`](../../../docs/drivers/OpcUaClient-Test-Fixture.md)
+for the full coverage map + what's still trusted from field deployments.
+
+## References
+
+- [opc-plc GitHub](https://github.com/Azure-Samples/iot-edge-opc-plc)
+- [mcr.microsoft.com/iotedge/opc-plc tags](https://mcr.microsoft.com/v2/iotedge/opc-plc/tags/list)
+- [`docs/drivers/OpcUaClient-Test-Fixture.md`](../../../docs/drivers/OpcUaClient-Test-Fixture.md)