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/docker-compose.yml

@@ -0,0 +1,45 @@
+# opc-plc — OPC UA PLC simulator from Microsoft Industrial IoT.
+# https://github.com/Azure-Samples/iot-edge-opc-plc
+#
+# Why pinned: MCR tags only go forward; keeping the suite reproducible means
+# we test against a known feature surface. Bump deliberately alongside a
+# driver-side change that needs the newer image.
+services:
+  opc-plc:
+    image: mcr.microsoft.com/iotedge/opc-plc:2.14.10
+    container_name: otopcua-opc-plc
+    restart: "no"
+    ports:
+      - "50000:50000"
+    command:
+      # --pn:  Bind port 50000 (opc-plc default; matches fixture default)
+      # --ut:  Advertise an Unsecured transport endpoint (SecurityPolicy=None).
+      #        Tests that need signed/encrypted endpoints pick those off the
+      #        negotiated endpoint list separately — opc-plc always advertises
+      #        the secure policies even with --ut on.
+      # --aa:  Auto-accept client certs. Tests wouldn't otherwise survive the
+      #        first contact because opc-plc's cert trust store lives inside
+      #        the container + resets each spin-up.
+      # --daa: Disable anonymous auth — forces the driver to go through the
+      #        Anonymous user-token policy negotiation rather than opc-plc's
+      #        "no auth required" short-circuit. Would flip to username/cert
+      #        if we needed that coverage.
+      #        Commented out for first-pass smoke; flip on when the cert-auth
+      #        and username-auth smoke tests land.
+      # --alm: Turn on alarm simulation (TripAlarm / ExclusiveDeviation /
+      #        NonExclusiveLevel / DialogCondition). Closes the IAlarmSource
+      #        gap the OpcUaClient-Test-Fixture doc calls out.
+      - "--pn=50000"
+      - "--ut"
+      - "--aa"
+      - "--alm"
+      # - "--daa"
+    healthcheck:
+      # opc-plc doesn't expose an HTTP health endpoint by default; use a TCP
+      # probe via a shell the base image ships with. The fixture does its own
+      # TCP probe but healthcheck surfaces status in `docker ps` for humans.
+      test: ["CMD-SHELL", "netstat -an | grep -q ':50000.*LISTEN' || exit 1"]
+      interval: 5s
+      timeout: 2s
+      retries: 10
+      start_period: 10s