Task #222 partial — unblock AB Legacy PCCC via cip-path workaround (5/5 stages)

Replaced the "ab_server PCCC upstream-broken" skip gate with the actual
root cause: libplctag's ab_server rejects empty CIP routing paths at the
unconnected-send layer before the PCCC dispatcher runs. Real SLC/
MicroLogix/PLC-5 hardware accepts empty paths (no backplane); ab_server
does not. With `/1,0` in place, N (Int16), F (Float32), and L (Int32)
file reads + writes round-trip cleanly across all three compose profiles.

## Fixture changes

- `AbLegacyServerFixture.cs`:
  - Drop `AB_LEGACY_TRUST_WIRE` env var + the reachable-but-untrusted
    skip branch. Fixture now only skips on TCP unreachability.
  - Add `AB_LEGACY_CIP_PATH` env var (default `1,0`) + expose `CipPath`
    property. Set `AB_LEGACY_CIP_PATH=` (empty) against real hardware.
  - Shorter skip messages on the `[AbLegacyFact]` / `[AbLegacyTheory]`
    attributes — one reason: endpoint not reachable.

- `AbLegacyReadSmokeTests.cs`:
  - Device URI built from `sim.CipPath` instead of hardcoded empty path.
  - New `AB_LEGACY_COMPOSE_PROFILE` env var filters the parametric
    theory to the running container's family. Only one container binds
    `:44818` at a time, so cross-family params would otherwise fail.
  - `Slc500_write_then_read_round_trip` skips cleanly when the running
    profile isn't `slc500`.

## E2E + seed + docs

- `scripts/e2e/test-ablegacy.ps1` — drop the `AB_LEGACY_TRUST_WIRE`
  skip gate; synopsis calls out the `/1,0` vs empty cip-path split
  between the Docker fixture and real hardware.
- `scripts/e2e/e2e-config.sample.json` — sample gateway flipped from
  the hardware placeholder (`192.168.1.10`) to the Docker fixture
  (`127.0.0.1/1,0`); comment rewritten.
- `scripts/e2e/README.md` — AB Legacy expected-matrix row goes from
  SKIP to PASS.
- `scripts/smoke/seed-ablegacy-smoke.sql` — default HostAddress points
  at the Docker fixture + header / footer text reflect the new state.
- `tests/.../Docker/README.md` — "Known limitations" section rewritten
  to describe the cip-path gate (not a dispatcher gap); env-var table
  picks up `AB_LEGACY_CIP_PATH` + `AB_LEGACY_COMPOSE_PROFILE`.
- `docs/drivers/AbLegacy-Test-Fixture.md` + `docs/drivers/README.md`
  + `docs/DriverClis.md` — flip status from blocked to functional;
  residual bit-file-write gap (B3:0/5 → 0x803D0000) documented.

## Residual gap

Bit-file writes (`B3:0/5` style) surface `0x803D0000` against
`ab_server --plc=SLC500`; bit reads work. Non-blocking for smoke
coverage — N/F/L round-trip is enough. Real hardware / RSEmulate 500
for bit-write fidelity. Documented in `Docker/README.md` §"Known
limitations" + the `AbLegacy-Test-Fixture.md` follow-ups list.

## Verified

- Full-solution build: 0 errors, 334 pre-existing warnings.
- Integration suite passes per-profile with
  `AB_LEGACY_COMPOSE_PROFILE=<slc500|micrologix|plc5>` + matching
  compose container up.
- All four non-hardware e2e scripts (Modbus / AB CIP / AB Legacy / S7)
  now 5/5 against the respective docker-compose fixtures.

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

scripts/e2e/README.md

@@ -132,7 +132,7 @@ section to skip it.
 |---|---|---|
 | Modbus | — | **PASS** (pymodbus fixture) |
 | AB CIP | — | **PASS** (ab_server fixture) |
-| AB Legacy | `AB_LEGACY_TRUST_WIRE=1` | **SKIP** (ab_server PCCC path upstream-broken — task #222) |
+| AB Legacy | — | **PASS** (ab_server SLC500/MicroLogix/PLC-5 profiles; `/1,0` cip-path required for the Docker fixture) |
 | S7 | — | **PASS** (python-snap7 fixture) |
 | FOCAS | `FOCAS_TRUST_WIRE=1` | **SKIP** (no public simulator — task #222 lab rig) |
 | TwinCAT | `TWINCAT_TRUST_WIRE=1` | **SKIP** (needs XAR or standalone Router — task #221) |

scripts/e2e/e2e-config.sample.json

@@ -17,8 +17,8 @@
     },
 
     "ablegacy": {
-        "$comment": "Gated behind AB_LEGACY_TRUST_WIRE=1 — ab_server PCCC path upstream-broken, needs real SLC / MicroLogix / PLC-5 or RSEmulate 500.",
-        "gateway": "ab://192.168.1.10/1,0",
+        "$comment": "Works against ab_server --profile slc500 (Docker fixture) or real SLC/MicroLogix/PLC-5 hardware. `/1,0` cip-path is required for the Docker fixture; real hardware accepts an empty path — e.g. `ab://10.0.1.50:44818/`.",
+        "gateway": "ab://127.0.0.1/1,0",
         "plcType": "Slc500",
         "address": "N7:5",
         "bridgeNodeId": "ns=2;s=AbLegacy/N7_5"

scripts/e2e/test-ablegacy.ps1

@@ -4,16 +4,19 @@
   End-to-end CLI test for the AB Legacy (PCCC) driver.
 
 .DESCRIPTION
-  **KNOWN-BROKEN upstream (ab_server PCCC dispatcher gap, verified 2026-04-21).**
-  Works against real SLC / MicroLogix / PLC-5 hardware or a RSEmulate 500
-  golden-box. Against the Docker ab_server the tests deliberately skip —
-  same gate as tests/.../AbLegacy.IntegrationTests (AB_LEGACY_TRUST_WIRE=1).
+  Runs against libplctag's ab_server PCCC Docker fixture (one of the
+  slc500 / micrologix / plc5 compose profiles) or real SLC / MicroLogix /
+  PLC-5 hardware. Five assertions: probe / driver-loopback / forward-
+  bridge / reverse-bridge / subscribe-sees-change.
 
-  Five assertions: probe / driver-loopback / forward-bridge / reverse-bridge /
-  subscribe-sees-change.
+  ab_server enforces a non-empty CIP routing path (`/1,0`) before the
+  PCCC dispatcher runs; real hardware accepts an empty path. The default
+  $Gateway uses `/1,0` for the Docker fixture — pass `-Gateway
+  "ab://host:44818/"` when pointing at a real SLC 5/05 / MicroLogix /
+  PLC-5.
 
 .PARAMETER Gateway
-  ab://host[:port]/cip-path. Default ab://127.0.0.1/1,0.
+  ab://host[:port]/cip-path. Default ab://127.0.0.1/1,0 (Docker fixture).
 
 .PARAMETER PlcType
   Slc500 / MicroLogix / Plc5 / LogixPccc (default Slc500).
@@ -39,13 +42,10 @@ param(
 $ErrorActionPreference = "Stop"
 . "$PSScriptRoot/_common.ps1"
 
-# Skip-gate: the driver CLI's underlying AbLegacyServerFixture-equivalent
-# check — operators point at real hardware by setting AB_LEGACY_TRUST_WIRE=1.
-# Without the opt-in we skip (don't run against the known-broken ab_server).
-if (-not ($env:AB_LEGACY_TRUST_WIRE -eq "1" -or $env:AB_LEGACY_TRUST_WIRE -eq "true")) {
-    Write-Skip "AB_LEGACY_TRUST_WIRE not set — skipping (ab_server PCCC is upstream-broken; set =1 against real hardware / RSEmulate)."
-    exit 0
-}
+# ab_server PCCC works; the earlier "upstream-broken" gate is gone. The only
+# caveat: libplctag's ab_server rejects empty CIP paths, so $Gateway must
+# carry a non-empty path segment (default /1,0). Real SLC/PLC-5 hardware
+# accepts an empty path — use `ab://host:44818/` when pointing at real PLCs.
 
 $abLegacyCli = Get-CliInvocation `
     -ProjectFolder "src/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.Cli" `

scripts/smoke/seed-ablegacy-smoke.sql

@@ -1,15 +1,17 @@
 -- AB Legacy e2e smoke seed — closes #213 (umbrella #209).
 --
--- Hardware-gated. The ab_server PCCC dispatcher is upstream-broken (task #222
--- tracks the lab rig + alternative fixtures), so verifying this seed end-to-end
--- requires real SLC 500 / MicroLogix / PLC-5 hardware or an RSEmulate 500
--- golden-box. The factory + seed ship here so the wiring is in place the
--- moment real hardware becomes available — no server code changes needed.
+-- Works against the ab_server PCCC Docker fixture (one of the slc500 /
+-- micrologix / plc5 compose profiles) or real SLC 500 / MicroLogix / PLC-5
+-- hardware. Default HostAddress below points at the Docker fixture with a
+-- `/1,0` cip-path; libplctag's ab_server rejects empty paths before routing
+-- to the PCCC dispatcher. Real hardware uses an empty path — change the
+-- HostAddress to `ab://<plc-ip>:44818/` (note the trailing slash with nothing
+-- after) before running the seed for that setup.
 --
--- Usage (once hardware is reachable):
+-- Usage:
+--   docker compose -f tests/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy.IntegrationTests/Docker/docker-compose.yml --profile slc500 up -d
 --   sqlcmd -S "localhost,14330" -d OtOpcUaConfig -U sa -P "OtOpcUaDev_2026!" \
 --          -i scripts/smoke/seed-ablegacy-smoke.sql
--- (Update the `HostAddress` below to point at the real gateway first.)
 
 SET NOCOUNT ON;
 SET XACT_ABORT ON;
@@ -83,7 +85,7 @@ VALUES (@Gen, @DrvId, @ClusterId, @NsId, 'ablegacy-smoke', 'AbLegacy', N'{
   "TimeoutMs": 2000,
   "Devices": [
     {
-      "HostAddress": "ab://192.168.1.10/1,0",
+      "HostAddress": "ab://127.0.0.1:44818/1,0",
       "PlcFamily": "Slc500",
       "DeviceName": "slc-500"
     }
@@ -92,7 +94,7 @@ VALUES (@Gen, @DrvId, @ClusterId, @NsId, 'ablegacy-smoke', 'AbLegacy', N'{
   "Tags": [
     {
       "Name": "N7_5",
-      "DeviceHostAddress": "ab://192.168.1.10/1,0",
+      "DeviceHostAddress": "ab://127.0.0.1:44818/1,0",
       "Address": "N7:5",
       "DataType": "Int",
       "Writable": true,
@@ -117,6 +119,7 @@ PRINT '  Cluster:    ' + @ClusterId;
 PRINT '  Node:       ' + @NodeId;
 PRINT '  Generation: ' + CONVERT(nvarchar(20), @Gen);
 PRINT '';
-PRINT 'NOTE: hardware-gated. ab_server PCCC is upstream-broken (#222). Point the';
-PRINT '      DriverConfig HostAddress at real SLC / MicroLogix / PLC-5 / RSEmulate';
-PRINT '      and run the e2e script with AB_LEGACY_TRUST_WIRE=1.';
+PRINT 'NOTE: default points at the ab_server slc500 Docker fixture with a /1,0';
+PRINT '      cip-path (required by ab_server). For real SLC/MicroLogix/PLC-5';
+PRINT '      hardware, edit the DriverConfig HostAddress to end with /<empty>';
+PRINT '      e.g. "ab://<plc-ip>:44818/" and re-run this seed.';