M1: make COMTRADE open native-only

[masarray]

Scope

• preserve the current FAT/workstation UX fixes on fix/gui-ux-comtrade-inprocess-m1
• keep Fault Records COMTRADE Open strictly in-process/native-only
• restore the last field-accepted rich ARSAS COMTRADE workstation instead of following newer regressed ArdIrec UI work

COMTRADE workstation provenance

The rich viewer restored here comes from ARSAS commit c3e2ac3ef6e6a3a49f47c5155a0ba4a7c00bcb6b (P1D.7: integrate production COMTRADE workstation). It restores the ARSAS-native engineering surfaces that were lost when the FAT branch evolved separately:

• Time Signals / disturbance workstation
• Phasor
• Harmonics
• six-loop native Locus
• cursor measurements
• RMS / recorded-secondary-primary display semantics
• investigation timeline/shell and bounded performance behavior

The analysis engine is deliberately pinned to the field-tested ArdIrec bridge snapshot used by that workstation, not ArdIrec latest/main:

• repository: masarray/ardirec
• ref: feat/p1d5-arsas-analysis-bridge
• commit: 7dbc7149db668126a493ce338264363a6ec5ec00
• ABI: 1, native-only
• capabilities: cursor measurement, channel semantics, value representation, status state, digital edge snap, phasor, harmonics, distance locus

Preserved native-only guards

• no ardirec.exe launch
• no Qt runtime packaging
• no Process.Start COMTRADE fallback
• FaultRecordWindow.ComtradeOpen.cs remains routed to ArdIrecNativeBridge.TryOpen + ComtradeWorkspaceWindow
• installer/staging explicitly rejects legacy ArdIrec desktop/Qt files
• current FAT/MainWindow implementation was not replaced by the historical COMTRADE snapshot

Earlier UX fixes retained

• remove legacy first-run FAT launcher card
• converge FAT workspace shell with other Engineering tabs
• compact Live Monitor header into one row with bounded search

Current integration commits

• 26cacbac0357477b7a14c8b08d999ed763c30ce4 — restore field-accepted COMTRADE workstation
• 782a3249385d3923336b2e2567bcca8b3c24b02b — validate field-tested ArdIrec analysis pin
• 962f79dcab6c08180fc408b097d5b76e8a538e4b — align installer validation with field-tested COMTRADE pin

Validation

GitHub Actions for current head 962f79dcab6c08180fc408b097d5b76e8a538e4b have been triggered. At the latest check the runners are still queued, so this PR remains Draft and no green claim is made for the new transplant yet.