Post-M3.H Studio: firmware identity, guarded PTP recovery, USB and operator UX acceptance #300

Purpose

Single canonical post-M3.H engineering backlog for Studio operator visibility, device lifecycle and PTP error recovery. This is not part of the already published M3.H Public Stable Lab Simulator. Preserve main as the new development base and keep firmware Build ID a922e9bdba4e57a4 and all release binaries immutable.

Retired historical PR candidates (source preserved, not silently merged)

• feat(p0): center-screen actionable Studio toast for board faults, PTP Ethernet and operator attention #272 a03da5e5a1de13daa9aa30bf23ed08419b4178d4 — actionable center-screen PHY/PTP/operator toast, Advanced-window feedback.
• P0 physical PTP stale-role recovery + verified Time Sync clipboard #266 799b66481f77abdcbdb50a6f1cab5fe165ade006 — reject-stale-role START, bounded STOP/ACK/readback retry, Time Sync clipboard diagnostics.
• P0 Studio: exact firmware build identity and stage-aware PTP START recovery #263 8d50911172d4f2c52fdf950f5c33f255e90ef351 — exact flashed/observed firmware build identity and stage-aware PTP startup.
• P0 Studio field fixes: delayed USB firmware verification, truthful START, capture phase evidence #259 a852170c2e990eb75d2b8c024942f3a494651e8e — post-flash identity pending, USB reconnect and SV capture telemetry UX.
• P0 Studio operator UX: table-as-wire SSOT, visible injector title, stacked 4I+4V, centered controls #239 c35c73fe59ee45cc0d2149152c5969fb0b4a5807 — operator screen layouts / 4I+4V wire-table consistency, phase update propagation.

All are old stacked/divergent branches from before validated M3.H firmware, not approved as current product fixes. The cited branch SHAs remain reachable; do not use old PR's merge button or copy raw embedded code. For each item, compare actual function-level behavior with current main and mark either already implemented, obsolete, or still missing with a unit/UI reproducer.

Acceptance for future new PR from current main

• Verify selected ESP32-P4 identity with exact firmware Build ID, not only semantic v0.1.1.
• Before modifying PTP role, inspect true board state; bounded STOP/ACK/readback with no stale apparent OFF, no silent role-force and no automatic SV start.
• All errors (link disconnected, serial mismatch, phase unqualified, START refused, timeout) have concise actionable Studio presentation; never hide substantive errors behind a transient success toast.
• 4I+4V operator values and actual wire transaction have a testable SSOT; no partial intermediate updates claimed atomic without firmware ACK proof.
• Windows Qt and deterministic harness CI, USB disconnect/reconnect and operator-view screenshot evidence on exact new source SHA.
• Regression against M3.H 4 kHz, PTP SOURCE continuity and smpSynch AUTO; capture and checksum paired with newly built firmware. Do not overwrite M3.H release assets.
• Physical test evidence for stale-role/USB fault paths that depend on hardware.

This issue owns the unimplemented remainder only. M3.H release-to-main ledger. Related: #42 (atomic live SV), #287 (actual external GM PTP failure), #154 and #162 (physical PTP/SV acceptance).