[plugin-dashboard] DashboardGridLayout has no legacy-widget fallback — a retired inline-analytics widget renders a silent blank chart where DashboardRenderer shows the rebind prompt #4612

Filed by the PM from the #4600 measure seat's report (§1 secondary finding; OQ1 ruled A). Duplicate-searched: no open issue mentions DashboardGridLayout at filing time.

The defect

The framework#3320 retirement gave DashboardRenderer a legacy sentinel: a widget carrying the retired inline-analytics shape (top-level object + categoryField/aggregate, and the pivot family) selects the LEGACY_RETIRED_WIDGET_SCHEMA placeholder (DashboardRenderer.tsx:142-155, sentinel read at :549, pivot family at :703-709) — a visible "This widget uses a retired data format. Edit it to bind a dataset." tile with a rebind affordance.

DashboardGridLayout — a SEPARATE exported surface used by DashboardWithConfig / editable dashboards — has NO such sentinel. A legacy widget falls through to the static-data branch with data: [] (DashboardGridLayout.tsx:215-225), i.e. a silent blank chart. That is the exact outcome the retirement's own test header says must not happen, and it is worse than the pre-retirement state for the user: no chart, no diagnostic, no path to fix.

Blast radius

Editable dashboards (DashboardWithConfig consumers) rendering any stored dashboard authored before the retirement. DashboardRenderer's own path is fine — the two surfaces just disagree.

Fix shape

Give DashboardGridLayout the same legacy detection and the same placeholder (share the sentinel/placeholder rather than hand-copying it — one detector, two consumers), with a red-first pin mirroring DashboardRenderer.legacyRetired.test.tsx's 4-positive/2-negative structure on the GridLayout surface. Must-not-change: dataset widgets, options.data provider config (a DIFFERENT, live surface — see the #4600 measurement's do-not-conflate note), and static-data widgets keep rendering.

Refs #4600 (measurement, comment 5287946890), framework#3320.

Generated by Claude Code