P3-H P1.3: fail-closed SCL nofASDU provenance

[masarray]

Closes #147 after exact-head CI acceptance. Continues #139.

Base main@0a08767df0352b0311fdcf5d31a9782ccba1a13b (merged P1.2 #145).
Exact head 76749d5718affb738a45cd6845c120ce9363da0f.

Problem

Previously max(1, ushort_attribute(nofASDU)) silently turned explicit zero, malformed or overflow SCL into valid one-ASDU engineering intent.

Change

• Omission alone retains compatibility default one ASDU.
• Explicit invalid values (0, lexical garbage, overflow, empty) retain no_asdu_valid=false and generate diagnostics.
• Profile compiler rejects malformed explicit packetization.
• Canonical exporter rejects laundering invalid input into valid SCL.
• Workspace semantic equivalence includes validity provenance.
• Regression fixtures cover omission, valid 1/2 and four invalid cases; negative export/compile checks.

No changes to hardware realtime path, packet encoder, IEC 61869-9 scaling/variant authority, or existing valid streams. Review and exact-head CI required before merge.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-07T00:54:10.702312Z	76749d5	Draft marked ready

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