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.FOCAS.IntegrationTests/Docker/focas-mock/VENDORED.md

@@ -0,0 +1,45 @@
+# focas-mock — vendored snapshot
+
+Source: `C:\Users\dohertj2\Desktop\focas` (sibling project in this dev environment).
+
+**Snapshot date:** 2026-04-24 (second refresh — pulled the native FOCAS2 Ethernet responder work in).
+
+## Why vendored
+
+OtOpcUa's FOCAS integration fixture runs against the Python mock server.
+The upstream lives in its own repo; this directory is a verbatim
+snapshot so CI can build the Docker image without network access to the
+source repo and so OtOpcUa's test matrix pins a known-good revision.
+
+The managed `WireFocasClient` speaks the mock's native FOCAS2 Ethernet
+binary protocol directly — there's no longer a companion shim DLL.
+
+## What's here
+
+| Path | Purpose |
+|------|---------|
+| `src/focas_mock/` | Python package — TCP JSON/line-delimited mock server with 6 Fanuc CNC profiles |
+| `pyproject.toml` | Package metadata; installs `focas-mock` CLI |
+| `Dockerfile` | `python:3.11-slim` image built by the parent `docker-compose.yml` |
+| `README.md` | Upstream README |
+| `LICENSE` | MIT — permissive, vendoring allowed |
+
+
+## Refreshing the snapshot
+
+When upstream ships changes worth pulling:
+
+```powershell
+$src  = "C:\Users\dohertj2\Desktop\focas"
+$dest = "$PWD"
+Remove-Item -Recurse -Force "$dest\src" 2>$null
+Copy-Item -Recurse "$src\src" "$dest\src"
+Copy-Item "$src\pyproject.toml" "$dest\"
+Copy-Item "$src\README.md" "$dest\"
+Copy-Item "$src\LICENSE" "$dest\"
+Copy-Item "$src\Dockerfile" "$dest\"
+```
+
+Update the snapshot date at the top of this file afterward. No other
+files belong here — the Docker build context is just the Python package
+and its metadata.