Finding 005 revised approach: keep the parent Structure tag in
`_tagsByName` so the whole-UDT grouping planner can find it (required
for Driver.AbCip-003 opt-in path + alarm projection). Instead, detect a
direct read of a Structure-with-Members in `ReadSingleAsync` and return
`BadNotSupported` rather than Good/null — explicitly documenting the
contract that callers must address member paths. Duplicate-key checks
(scalar and member fan-out) remain.
Finding 014 test corrections: `Structure_parent_tag_read_returns_BadNotSupported`
now asserts the new contract. `Read_UDInt_tag_returns_uint_value_not_negative_wrapped_int`
assertion fixed to use `ShouldBeOfType<uint>()` instead of
`ShouldNotBe(-1)` (Shouldly overflows comparing uint.MaxValue with int).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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