feat(dashboard): time-varying threshold specs in FastSenseWidget

[HanSur94]

Motivation

FastSense core already supports dynamic (time-varying) thresholds — addThreshold(thX, thY, ...) draws step-function limits with full violation detection (compute_violations_dynamic + violation_cull MEX), label tracking on zoom, and clone support. But the Dashboard layer couldn't reach it: FastSenseWidget's 'Thresholds' option only understood scalar struct('Value',..) entries.

This matters for state-dependent limits (the classic case: a band that only applies while a machine is MEASURING). Discovered converting a legacy Zeiss monitoring system whose plots drew exactly such per-sample threshold series — dashboards built on FastSenseWidget had no way to reproduce them.

Change

Spec entries may now carry X/Y vectors instead of Value:

engine.addWidget('fastsense', 'Tag', sensorTag, 'Thresholds', { ...
    struct('Value', 28.5, 'Direction', 'upper', 'Label', 'UAL'), ...          % scalar, as before
    struct('X', thX, 'Y', thY, 'Direction', 'upper', 'Label', 'UWL')});       % time-varying

• applyThresholds_ forwards X/Y entries to the core's existing time-varying form; NaN Y samples mean no limit here and break the drawn line
• Scalar and time-varying entries mix freely in one spec; scalar behavior unchanged
• autoscaleY_ folds the finite part of Y series into the auto Y-range (omitnan), matching scalar-Value handling

No core (FastSense.m) changes — pure pass-through plumbing.

Testing

• testTimeVaryingThresholdSpecReachesFastSense — X/Y entry creates exactly one core threshold, keeps its per-sample series, carries no scalar Value, preserves Direction/Label
• testMixedScalarAndTimeVaryingThresholds — both forms coexist in one spec
• mh_style / mh_lint clean; MATLAB Code Analyzer clean on the touched regions (remaining findings pre-exist on main)
• Exercised end-to-end (rendered, hidden + visible) against R2025b/macOS via an identical patch on a vendored snapshot driving 39 production-shaped dashboards

🤖 Generated with Claude Code

[codecov]

Codecov Report

❌ Patch coverage is 95.23810% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
libs/Dashboard/FastSenseWidget.m	95.23%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[HanSur94]

Reviewed: diff is backward-compatible (scalar specs unchanged, X/Y + Color/LineStyle additive), autoscale correctly folds finite Y with omitnan and skips all-NaN series. Local TestFastSenseWidget: 19/19 passed (R2025b). CI: sole failure is the pre-existing testPreviewStillFull render-cache regression on main (first red at 2355661) — unrelated to this PR.

🤖 Generated with Claude Code