M2.1: typed Quality evidence and fail-closed MMS bitstring decoding

[masarray]

Baseline and safety

Built on existing ARSAS Browser M1.5/M2 draft branch at 0a663ec; pinned engine 036e2c00d83a0815b6160147b14ea05975057965 unchanged. Never merged to stable main. No RCB/GI, report planning, dynamic polling, commands, SCL export, or release modifications.

Implemented — first incremental M2.1 slice

• Replace lossy Quality string-only decoder internals with typed 13-bit IEC evidence (Validity, detail flags, Source, Test, OperatorBlocked), strict significant-width/padding checks, and compatibility formatting.
• Restrict MMS Read Dbpos to exactly 2 significant bits; prevent schema-qualified Quality/Dbpos BIT STRING from being misinterpreted by generic fallback.
• Add shared operator presentation adapter and explicit schema-qualified Quality/Time row identity for IED Browser. Parent q/child fields use real bits when present; missing bits remain Not exposed.
• Add deterministic tests for four validity states, eleven flags, nonzero padding, malformed widths, missing flags and unchanged four-state Dbpos presentation.

Gates

Requires CI Windows regression at exact SHA; no physical ZIV AVR/BCUGE claim. Follow-up is engine-side typed observation ingress, shared per-IED live store, hierarchical details, Quick Start and COMTRADE workflow. Keep draft; no merge to main or public release without explicit operator approval.

[masarray]

M2.1 first-code checkpoint — verified Windows CI

• Exact tested head: 76be1df01d1e7933f1e4403ea23ba848e751ec9d
• CI: https://github.com/masarray/arsas/actions/runs/38485356158 — SUCCESS
• Pinned ARIEC tests: 19/19 passed
• ARSAS regression tests: 1,807/1,807 passed
• Packaged-runtime tests: 6/6 passed
• WPF build, native bridge integration, portable-single-EXE publication and smoke test: passed
• Artifact: ARSAS-win-x64-portable-single-exe (ID 11860315400) under this run

No public stable or engine-lock change. No physical device acceptance claimed. Current scope is the typed Quality/Dbpos-safe MMS Read presentation slice of M2.1; typed report ingress, timestamp evidence propagation and unified live state are the next work, not yet complete. Existing warnings in older tests remain non-blocking.