Add crosshair-link toggle to FastSense dashboard widgets (260602-mri)

.planning/STATE.md

@@ -27,7 +27,7 @@ Phase: 1040
 Plan: Not started
 Milestone: v3.0 FastSense Companion — SHIPPED 2026-04-30; v4.0 Multi-User LAN Concurrency — shipping via PR #152 (parallel branch); v1.0 perf line tracks phase 1028 — now COMPLETE via PR #114.
 Status: Phase complete — ready for verification
-Last activity: 2026-06-02
+Last activity: 2026-06-02 - Completed quick task 260602-mri: crosshair-link toggle on the FastSense widget bar (mirrors the hover crosshair across active-page FastSense widgets)
 
 ### Note on parallel v4.0 work (main branch state)
 
@@ -96,6 +96,7 @@ Other main PRs (#138, #139, #141, #144, #145, #146) auto-merged without conflict
 | 260526-pqz | Raise per-signal slider-preview cap from 400 → 1000 buckets in `DashboardEngine.computePreviewEnvelopeReturning_` — three textual edits (1 code clamp + 2 documenting comments) in `libs/Dashboard/DashboardEngine.m` plus one consistency comment in `tests/test_dashboard_preview_overlay.m` (no assertion change; `numel(xd) >= 4` is cap-independent). Edit sites: line 3524 doc-comment (`computePreviewEnvelope` range), line 3542 inline comment (clamp range), line 3555 actual clamp `max(50, min(1000, floor(axWpx / 2)))`. Out of scope per plan: cache invalidation of `PreviewNBuckets_` — running demos must restart (or trigger the existing resize-invalidation path at `DashboardEngine.m:2241`) for the new cap to take effect. Static analysis clean: `mh_lint` + `mh_style` on both edited files report "everything seems fine"; regression sweep `grep -rn "\b400\b" tests/ \| grep -iE "(preview\|bucket\|envelope)"` returns no matches. MATLAB R2025a: `test_dashboard_preview_envelope` 7/7, `test_dashboard_preview_overlay` 10/10. Octave 11.1.0: `test_dashboard_preview_envelope` 2/2 (5 skipped — pre-existing TimeRangeSelector guard for patch+FaceAlpha+NaN on xvfb), `test_dashboard_preview_overlay` skipped entirely (pre-existing). | 2026-05-26 | 834b43c | — | [260526-pqz-raise-preview-line-cap-per-signal-from-4](./quick/260526-pqz-raise-preview-line-cap-per-signal-from-4/) |
 | 260529-rxf | Real per-event email alerts for background monitoring — new `EmailTransport` (SMTP auth/STARTTLS:587 default, also `none`/`ssl`; Octave `exist('sendmail','file')` log-and-skip guard; pure static `buildMailProps` CI seam) that `NotificationService` now delegates to via an injectable `Transport` property; per-(sensor,threshold) email cooldown (default 5 min, 0 disables; dry-run honors it too) with public `SuppressedCount`; `LiveEventPipeline.processMonitorTag_`/`runCycle` now forward real per-event `sensorData` (X/Y/thresholdValue/thresholdDirection from the live tick) so `IncludeSnapshot` rules attach PNGs in live mode. MATLAB-only per user decision. **Backward-compat preserved**: pipeline still defaults to `NotificationService('DryRun', true)` and all prior tests stay green. Verified locally (R2025a, live MATLAB MCP): `test_email_transport` 5/5, `test_notification_service` 10/10 (7 original + 3 new: delegation / cooldown-suppress / cooldown-expiry-via-Hidden-DI-seam), `test_live_event_pipeline_tag` 3/3, plus class suites `TestEmailTransport` 5/5, `TestNotificationService` 7/7, `TestLiveEventPipelineTag` 3/3. MISS_HIT (`mh_style`+`mh_lint`) clean on all 8 files; MATLAB Code Analyzer clean on the 3 new/edited libs. Real SMTP delivery is the single manual step via `examples/05-events/smoke_email_send.m` (FASTSENSE_SMTP_* env vars, STARTTLS:587), out of CI. | 2026-05-29 | 203da7a, 2ac6887, 341bab2, cef1fc5 | Verified | [260529-rxf-real-per-event-email-alerts-for-backgrou](./quick/260529-rxf-real-per-event-email-alerts-for-backgrou/) |
 | 260529-fnt | Add `FunctionTransport` adapter (`libs/EventDetection/FunctionTransport.m`) — wraps a user-supplied function handle as a `NotificationService` `Transport` so an existing site/company MATLAB mailer can be reused for alerts with **no SMTP config** (no server/port/creds, no Gmail App Password). Drop-in duck-typed `send(recipients,subject,body,attachments)` (same as EmailTransport), normalizes recipients to a flat cellstr, defaults attachments to `{}`, Octave-safe (only calls user code). Purely additive — EmailTransport/NotificationService behavior unchanged. Built via **/gsd:fast** (inline, no subagents). Verified (R2025a): `test_function_transport` 5/5 (forwarding / recipients-normalization / attachments-default / invalid-handle / NotificationService integration), `test_notification_service` 10/10 (no regression); MISS_HIT + Code Analyzer clean on all touched files. `example_live_pipeline.m` gains a commented FunctionTransport option. Follow-up to 260529-rxf after the user opted to reuse their company mailer instead of configuring Gmail SMTP. | 2026-05-29 | 706e9d5 | Verified | (inline) |
+| 260602-mri | Add a crosshair-link toggle ('X') to the FastSenseWidget grey WidgetButtonBar that mirrors the hover crosshair across all FastSense widgets on the **active dashboard page**. New `CrosshairLinked` public property + `setCrosshairLink(tf)` on `FastSenseWidget` (default OFF; `toStruct` omits when false so legacy serialized dashboards are byte-identical; `fromStruct` restores). `HoverCrosshair` gains `setBroadcastFcn`/`onMoveExternal`/`onLeaveExternal` + a **deterministic `IsMirrored_` suppress flag** so a mirrored peer's same-dispatch self-leave is a no-op — **ZERO new figure-WBM closures**, respecting the 260512-egv/eu2 chained-WBM constraint; the broadcast rides on existing per-crosshair `onMove`/`onLeave` and each peer computes its OWN per-series datatip at the shared data-x via `computeYAtX_` (raw-x, no Y transmitted). `DashboardEngine` derives the active-page link set on demand (`collectLinkedCrosshairs_`, flattens GroupWidget children via `flattenWidgetsForPreview_`) through `broadcastCrosshairX_`/`broadcastCrosshairLeave_`/`onCrosshairLinkToggle`, and re-primes broadcast hooks via `rewireCrosshairLinks_` after `rerenderWidgets`/`switchPage`/`detachWidget`. Duck-typed 'X' button injected in `DashboardLayout.realizeWidget` via `ismethod(widget,'setCrosshairLink')` (leftmost chrome button, left of V/A), re-anchored by `reflowChrome_`, protected in `DashboardWidget.clearPanelControls`. **Orchestrator verification (R2025a, live MCP)** replaced the executor's flaky `tic`-window suppress (`SuppressLeaveUntil_`/`SuppressWindow_` — passed in isolation, failed in-suite) with the deterministic `IsMirrored_` flag, and fixed a **latent unbounded leave ping-pong** (`onLeaveExternal` now hides directly via a private `hideGraphics_` instead of re-entering broadcasting `onLeave`). Tests: new `test_fastsense_crosshair_link` **11/11**; regressions green (`test_hover_crosshair` 11/11, `test_fastsense_widget_ylimit_modes` 11/11, `test_time_range_selector_reinstall_after_rerender` pass, `test_dashboard_time_sync_all_pages` 5/5); MISS_HIT clean on all 6 files; Code Analyzer no new findings; live UI smoke on a rendered 2-widget dashboard (button renders + toggles, hovering one linked widget mirrors crosshair+datatip on the other, leave hides both, unlink stops mirroring). DetachedMirror crosshair-link parity OUT OF SCOPE (detached widgets use a figure-level `FastSenseToolbar`, not a WidgetButtonBar — matches 260513-sfp). | 2026-06-02 | a495cbc9, 635632e2, 8950abd5, 485154b7 | Verified | [260602-mri-add-crosshair-link-toggle-to-fastsense-w](./quick/260602-mri-add-crosshair-link-toggle-to-fastsense-w/) |
 
 ## Progress Bar