fix(ablegacy): refuse every libplctag write the #659 translation changes (fix round 2)

Review M1: round 1 refused only the rewritten status bits, so S:/O:/I: writes - which
never worked on libplctag because tag creation failed - would have started reaching
the PLC (outputs, status-file words) on the default transport. WriteRefusal now keys
on LibplctagLegacyName.IsTranslated: file number supplied (S/O/I, incl. bit writes
like O:0/3, refused ahead of the parent-word RMW) or status bit rewritten. Reads
unaffected. Docs/comments now true; gate doc notes R bit-number wire evidence is
non-discriminating (L1). 12 new cases fail with the round-1 predicate.

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

CLAUDE.md

@@ -1094,8 +1094,9 @@ re-emit a concrete default. The defaults differ per driver (final review, 2026-1
   used to fail `S:`/`O:`/`I:` and `R` status bits there (incl. the default probe `S:0`) — its `pccc.c` needs explicit
   file numbers and has no R status-bit mnemonics; since #659 `LibplctagLegacyName` translates (`S2:`/`O0:`/`I1:`,
   `R6:0.CON/13`) and both transports read identically on that press. The authored grammar is unchanged. Read-side
-  only: a libplctag WRITE to a rewritten status bit (R `EN…FD`, `C…UA`) is refused `BadNotSupported` before any runtime
-  is created (it could never reach the PLC before); libplctag T/C status-bit writes it parses itself are unchanged.
+  only: a libplctag WRITE to any address the translation changes (`S:`/`O:`/`I:` incl. bit writes, R `EN…FD`, `C…UA`)
+  is refused `BadNotSupported` before any runtime is created (none could reach the PLC before — no write-surface
+  widening on the default transport); libplctag T/C status-bit writes it parses itself are unchanged.
   L/A files, function files, SLC, PLC-5 and `logixpccc` remain unverified natively. Explicit Native on PLC-5/`LogixPccc` logs a once-per-instance Warning.
   AbLegacy native refuses status-bit sub-element writes (`T4:0.DN`…, `BadNotSupported`).