docs(ab): hw4 evidence fix round 1 - bit-write gap provenance, README/CLI/fixture docs, libplctag-deletion gap

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe
2026-10-09 04:12:53 -04:00
parent 14ec145487
commit 9e894decb0
7 changed files with 37 additions and 31 deletions
@@ -243,7 +243,8 @@ The driver has two interchangeable wire transports, selected by one `DriverConfi
  Good). Still ab_server-only: array, STRING and UDT-member writes and fragmented writes. Mixed STRING/array/scalar
  Multiple Service Packet reads (#582) are proven on the press (one 5-read MSP, values equal to single reads). Results:
  [native-ab-transport-gate-results](../plans/2026-10-07-native-ab-transport-gate-results.md).
- **libplctag cannot be deleted** until a bench controller allows write verification.
+- **libplctag cannot be deleted yet.** Scalar native writes are proven on a CompactLogix (2026-10-09); what remains is #567
+  (fragmented wide-struct writes), array/STRING/UDT-member writes on hardware, and AbLegacy native (simulator-only, no PCCC hardware).
 - ⚠️ RESIDUAL (#567): wide-struct **fragmented writes** (8-byte alignment) are unit-tested only. Production
  presses are read-only and there is no bench controller, so this cannot be proven; it stays open until a
  bench controller exists.