Docs + code-comment sweep — remove stale Pymodbus/ + PythonSnap7/ + LocateBinary references left behind by the native-fallback removal PR. Answer to "is the dev inventory + documentation updated": it was partial; this PR finishes the job.

Files touched — docs/drivers/Modbus-Test-Fixture.md dropped the key-files pointer at deleted Pymodbus/ + flipped "primary launcher is Docker, native fallback retained" framing to "Docker is the only supported launch path" (matching the code). docs/v2/dev-environment.md dropped the "skips both Docker + native-binary paths" parenthetical from AB_SERVER_ENDPOINT + flipped the "Native fallbacks" subsection to a one-liner that says Docker is the only supported path. docs/v2/modbus-test-plan.md rewrote §Harness from "pip install pymodbus + serve.ps1" setup pattern to "docker compose --profile <…> up" + updated the §PR 43 status bullet to point at Docker/profiles/. docs/v2/test-data-sources.md §"CI fixture (task #180)" rewrote the AB CIP section from "LocateBinary() picks binary off PATH" + GitHub Actions zip-download step to "Docker is the only supported reproducible build path" + docker compose GitHub Actions step; dropped the pinned-version SHA256 table + lock-file reference because the Dockerfile's LIBPLCTAG_TAG build-arg is the new pin.

Code docstrings + error messages — these are developer-facing operational text too. ModbusSimulatorFixture SkipReason strings (both branches) now point at `docker compose -f Docker/docker-compose.yml --profile standard up -d` instead of the deleted `Pymodbus\serve.ps1`; doc-comment at the top references Docker/docker-compose.yml. Snap7ServerFixture SkipReason strings + doc-comment point at Docker/docker-compose.yml instead of PythonSnap7/serve.ps1. S7_1500Profile.cs docstring updated. Modbus Dockerfile comment pointing at deleted tests/.../Pymodbus/README.md redirected to docs/drivers/Modbus-Test-Fixture.md. DL205Profile.cs + DL205StringQuirkTests.cs + S7_1500Profile.cs (in Modbus project) docstrings flipped from Pymodbus/*.json references to Docker/profiles/*.json.

Left untouched deliberately: docs/v2/implementation/exit-gate-phase-2-closed.md — that's a historical as-of-2026-04-18 snapshot documenting what was skipped at Phase 2 closure; rewriting would lose the date-stamped context. Its "oitc/modbus-server Docker container not started" + "ab_server binary not on PATH" lines describe the fixture landscape that existed at close time, not current operational guidance.

Final sweep confirms zero remaining `Pymodbus/` / `PythonSnap7/` / `LocateBinary` / `AbServerSeedTag` / `BuildCliArgs` / `AbServerPlcArg` mentions anywhere in tracked files outside that historical exit-gate doc. Whole-solution build still 0 errors.

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

docs/v2/modbus-test-plan.md

@@ -13,9 +13,9 @@ confirmed DL205 quirk lands in a follow-up PR as a named test in that project.
 
 ## Harness
 
-**Chosen simulator: pymodbus 3.13.0** (`pip install 'pymodbus[simulator]==3.13.0'`).
-Replaced ModbusPal in PR 43 — see `tests/.../Pymodbus/README.md` for the
-trade-off rationale. Headline reasons:
+**Chosen simulator: pymodbus 3.13.0** packaged as a pinned Docker image
+under `tests/.../Modbus.IntegrationTests/Docker/`. See that folder's
+`README.md` for image-build notes + compose profiles. Headline reasons:
 
 - **Headless** pure-Python CLI; no Java GUI, runs cleanly on a CI runner.
 - **Maintained** — current stable 3.13.0; ModbusPal 1.6b is abandoned.
@@ -26,17 +26,18 @@ trade-off rationale. Headline reasons:
 - **Per-register raw uint16 seeding** — encoding the DL205 string-byte-order
   / BCD / CDAB-float quirks stays explicit (the quirk math lives in the
   `_quirk` JSON-comment fields next to each register).
-- Pip-installable on Windows; sidesteps the privileged-port admin
-  requirement by defaulting to TCP **5020** instead of 502.
+- **Dockerized** — pinned image means the CI simulator surface is
+  reproducible + no `pip install` step on the dev box.
+- Defaults to TCP **5020** (matches the compose port-map + the fixture
+  default endpoint; sidesteps the Windows Firewall prompt on 502).
 
 **Setup pattern**:
-1. `pip install "pymodbus[simulator]==3.13.0"`.
-2. Start the simulator with one of the in-repo profiles:
-   `tests\.../Pymodbus\serve.ps1 -Profile standard` (or `-Profile dl205`).
-3. `dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests` —
+1. `docker compose -f tests\...\Modbus.IntegrationTests\Docker\docker-compose.yml --profile <standard|dl205|mitsubishi|s7_1500> up -d`.
+2. `dotnet test tests\ZB.MOM.WW.OtOpcUa.Driver.Modbus.IntegrationTests` —
    tests auto-skip when the endpoint is unreachable. Default endpoint is
    `localhost:5020`; override via `MODBUS_SIM_ENDPOINT` for a real PLC on its
    native port 502.
+3. `docker compose -f ... --profile <…> down` when finished.
 
 ## Per-device quirk catalog
 
@@ -113,9 +114,11 @@ vendors get promoted into driver defaults or opt-in options:
 - **PR 42 — ModbusPal `.xmpp` profiles** — **SUPERSEDED by PR 43**. Replaced
   with pymodbus JSON because ModbusPal 1.6b is abandoned, GUI-only, and only
   exposes 2 of the 4 standard tables.
-- **PR 43 — pymodbus JSON profiles** — **DONE**. `Pymodbus/standard.json` +
-  `Pymodbus/dl205.json` + `Pymodbus/serve.ps1` runner. Both bind TCP 5020.
+- **PR 43 — pymodbus JSON profiles** — **DONE**. Dockerized under
+  `Docker/profiles/` (standard.json, dl205.json, mitsubishi.json,
+  s7_1500.json); compose file launches each via a named profile.
+  All bind TCP 5020.
 - **PR 44+**: one PR per confirmed DL205 quirk, landing the named test + any
   driver-side adjustment (string byte order, BCD decoder, V-memory address
   helper, FC16 cap-per-device-family) needed to pass it. Each quirk's value
-  is already pre-encoded in `Pymodbus/dl205.json`.
+  is already pre-encoded in `Docker/profiles/dl205.json`.