[Samfa12-tech]

Ordinary pack-path checks emitted Unexpected-NUL diagnostics because String.chr(0) warns and returns U+FFFD in Godot4.6.3. This replaces that construction with the same character directly, preserving the existing rejection behavior. A31check regression covers valid Unicode, invalid/traversal paths and intentional ZIP-directory versus asset-path differences; CI rejects NUL diagnostics in that probe.

The musical measurement harness also saved both native player modes to the same manifest-adjacent profile, overwriting the first. It now saves distinct profiles and verifies actual active-player ownership after Play. Previous duplicate-mode claims are withdrawn; the original evidence remains.

This is a separate follow-up to frozen PR143 2fb2f49df3659402d9290b6c6ed98dd2498ee700, rather than rewriting its independently reviewed source or artifacts. Its old hosted job tested merge a8ebba0dc53ca6f3e662de342c254f76738aa802 and retained206 NUL diagnostics; it is not relabelled as diagnostic-free or direct-head provenance.

Validation:

• All16 source-only Godot stages pass, including31 path-policy checks, with zero Unexpected-NUL messages. Ordinary unrelated routing warnings remain visible.
• Corrected current44.1k native export and retained48k425127frame conformance cases pass complete PCM/tail/natural-ending checks in both observed player modes. Current output uses a clearly scoped48k raw-player resampler control. Silence/final-frame truncation controls reject; maximum clock error below18.3ms, unchanged150ms bound.
• Four bounded automatic-versus-forced rendering controls retain exactPR143 source,45s stopped/15s music-SFX windows and explicit delay/CPU calibrations. Ordinary gaps below20.3ms; total frame gates fail by design and retain one89.252ms startup gap. Historical unexplained199/45/520ms and other earlier failures did not reproduce and remain acceptance holds. No threshold is waived.

See addons/pocket_chordsmith/docs/{NUL_DIAGNOSTIC_CAUSE_2026-10-17,RUNTIME_FOLLOWUP_2026-10-17}.md for exact scopes and superseding ledger. Production audio clock/renderer, released DAW/web/DJ/Core bytes, public Godot1.2.0 and Sam's listing prose remain unchanged. No final release ZIP, public upload, Store API access, microphone recording or deletion. Independent follow-up review and human/performance acceptance remain required before publication.

[Samfa12-tech]

Included through the exact reviewed history in release consolidation PR145, merged as 9e47f2c. Final16 CI/CodeQL checks passed; runtime bytes match reviewed e00f946. Closing this stacked follow-up as completed; its source branch and evidence remain preserved.