M3C.3: include PTP/GPTimer clock-read uncertainty in SV phase tracking

[masarray]

Root cause

The M3 software phase authority promoted software_tracking after N nominal phase readings within 60 µs, without accounting for uncertainty of the bracketed EMAC PTP/GPTimer clock read. A 400-µs read bracket could therefore satisfy the tracking predicate with >=201 µs uncertainty — an unfounded precision claim.

Fix

• Require abs(phase_error_us) + observation_uncertainty_us <= software_tracking_threshold_us before incrementing consecutive tracking samples.
• Degrade tracking on uncertain readings, without modifying O(1) ISR, bounded PI/slew, integer PTP-second continuity, SOURCE/RECEIVER clock lease or smpSynch=AUTO semantics.
• New portable positive/negative C++ regression: 6 high-uncertainty observations must not qualify despite exact nominal phase; 4 fresh narrow observations may qualify; one later degraded bracket revokes tracking.
• Add scope and physical-evidence limitation to M3C acceptance note.

Acceptance

Require exact-commit PTP Core CI GCC/Clang/MSVC before merge into experimental M3 base. Firmware hardware phase/egress and IED evidence still missing; no public release claim. Commit 02e30509d92743c88d3616417d22156ab5130c94.

Exact-head CI remediation discovered during review

• MSVC C4244 in pre-existing VLAN test was a narrowing uint32_t assignment to optional VLAN ID/PCP; replaced with explicit uint16_t/uint8_t constants (no wire change).
• The PTP MSVC workflow configured five M3 CTest targets without building their executables; all five are now explicit build targets, preserving the full test suite.
• ESP32-P4 realtime-boundary CI hardcoded an obsolete two-argument start_sample_clock call while M3 uses PTP epoch arguments. It now locates the current call but retains its no-logging-after-timer assertion. Removed an actual post-arm ESP_LOGI from the firmware START path, preventing console work after the ISR starts firing.

Newest exact head: c776e7b0f324e0bb9dae4e578495448ff00fdbdb. CI results must be read at this head; earlier superseded workflow failures must not be claimed as current validation. No physical PTP–SV phase or IED lock claim.

[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 2026-10-17T08:32:29.134070Z	02e3050	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.